refactor: genericize chart of accounts levels

[vindard]

Description

This PR will be to change the fixed-depth hierarchy of our current Chart of Accounts to an any-depth hierachy. The current Chart is made up of Categories, ControlAccounts and ControlSubAccounts. The new structure will simply have nested Nodes and Leaves.

The scope of this PR is simply to move our existing Charts implementation from the old hierarchy to the new hierarchy.

Segmentation

In the old model, account codes were derived sequentially based on the parent entity. In the new model, a SegmentationSchema will be defined for the chart and user-defined account codes will be validated against this schema. The schema contains information about:

• number of levels in the hierarchy, represented by number of segments
• the length of code as defined by the aggregate of fixed lengths of each segment/level

User-provided codes will be validated via:

• valid characters
• segmentation schema conformity
• uniqueness in the chart

Samples from Domain Projection

Old

ChartTree {
    id: ChartId(
        0200d1d3-59ec-44f8-891a-b3dbceebbe3e,
    ),
    name: "Test Chart",
    assets: ChartTreeCategory {
        name: "Assets",
        encoded_path: "10000",
        children: [
            ChartTreeControlAccount {
                name: "Loans Receivable",
                encoded_path: "10100",
                children: [
                    ChartTreeControlSubAccount {
                        name: "Fixed Loans Receivable",
                        encoded_path: "10101",
                    },
                ],
            },
        ],
    },
    liabilities: ChartTreeCategory {
        name: "Liabilities",
        encoded_path: "20000",
        children: [
            ChartTreeControlAccount {
                name: "User Checking",
                encoded_path: "20100",
                children: [
                    ChartTreeControlSubAccount {
                        name: "User Checking",
                        encoded_path: "20101",
                    },
                ],
            },
        ],
    },
    equity: ChartTreeCategory {
        name: "Equity",
        encoded_path: "30000",
        children: [
            ChartTreeControlAccount {
                name: "Shareholder Equity",
                encoded_path: "30100",
                children: [
                    ChartTreeControlSubAccount {
                        name: "Shareholder Equity",
                        encoded_path: "30101",
                    },
                ],
            },
        ],
    },
    revenues: ChartTreeCategory {
        name: "Revenues",
        encoded_path: "40000",
        children: [
            ChartTreeControlAccount {
                name: "Interest Revenue",
                encoded_path: "40100",
                children: [],
            },
        ],
    },
    expenses: ChartTreeCategory {
        name: "Expenses",
        encoded_path: "50000",
        children: [],
    },
}

New

ChartTreeAlt {
    id: ChartId(
        d2b8c01e-023e-46fd-bafe-0fed171741c6,
    ),
    name: "Test Chart",
    children: [
        Node {
            id: AccountSetId(
                9b2cdbe6-2371-4ba2-96bb-3d474ccb1348,
            ),
            reference: "assets",
            encoded_path: EncodedPath {
                value: "1",
            },
            parent: None,
            children: [
                Node {
                    id: AccountSetId(
                        134bd004-0b4f-4d2f-850b-8a3ddd602021,
                    ),
                    reference: "loans-receivable",
                    encoded_path: EncodedPath {
                        value: "10",
                    },
                    parent: Some(
                        EncodedPath {
                            value: "1",
                        },
                    ),
                    children: [
                        Node {
                            id: AccountSetId(
                                85450f8c-2f0b-4371-bdb1-5836ccded321,
                            ),
                            reference: "fixed-loans-receivable",
                            encoded_path: EncodedPath {
                                value: "100",
                            },
                            parent: Some(
                                EncodedPath {
                                    value: "10",
                                },
                            ),
                            children: [
                                Leaf {
                                    id: AccountSetId(
                                        4e1af726-ab76-485b-b95a-1dd3ecf85e7e,
                                    ),
                                    reference: "fixed-loans-receivable-01",
                                    encoded_path: EncodedPath {
                                        value: "1000",
                                    },
                                    parent: Some(
                                        EncodedPath {
                                            value: "100",
                                        },
                                    ),
                                },
                                Leaf {
                                    id: AccountSetId(
                                        c2d7f866-44a3-4e31-9ef2-d097c245dd33,
                                    ),
                                    reference: "fixed-loans-receivable-02",
                                    encoded_path: EncodedPath {
                                        value: "1001",
                                    },
                                    parent: Some(
                                        EncodedPath {
                                            value: "100",
                                        },
                                    ),
                                },
                            ],
                        },
                    ],
                },
            ],
        },
        Node {
            id: AccountSetId(
                d2c43bfb-ca25-439a-970b-8ee5b9589b50,
            ),
            reference: "liabilities",
            encoded_path: EncodedPath {
                value: "2",
            },
            parent: None,
            children: [
                Node {
                    id: AccountSetId(
                        48911139-8c90-4b53-b790-772dae253ca7,
                    ),
                    reference: "user-checking",
                    encoded_path: EncodedPath {
                        value: "20",
                    },
                    parent: Some(
                        EncodedPath {
                            value: "2",
                        },
                    ),
                    children: [
                        Node {
                            id: AccountSetId(
                                c4951a75-c1fd-4779-883d-351f5488eb0b,
                            ),
                            reference: "sub-user-checking",
                            encoded_path: EncodedPath {
                                value: "200",
                            },
                            parent: Some(
                                EncodedPath {
                                    value: "20",
                                },
                            ),
                            children: [
                                Leaf {
                                    id: AccountSetId(
                                        b38b520e-1fc0-49f3-a26d-5b1ad44363eb,
                                    ),
                                    reference: "sub-user-checking-01",
                                    encoded_path: EncodedPath {
                                        value: "2000",
                                    },
                                    parent: Some(
                                        EncodedPath {
                                            value: "200",
                                        },
                                    ),
                                },
                            ],
                        },
                    ],
                },
            ],
        },
    ],
}