Add mermaid graph to getAssetGraph()

[mandy-chessell]

Description

The PR builds on @dwolfson's work to use mermaid to render images of sections of the open metadata graph. It creates a visualization of an asset and its anchored elements.

Below is a screen capture of a rendered asset.

It is rendered from this string:

"---\ntitle: Asset - view-server [5ae81670-0710-45b7-94bf-6337871b7dc1]\n---\nflowchart LR\n%%{init: {\"flowchart\": {\"htmlLabels\": false}} }%%\n\nViewServer:view-server(\"`*SoftwareServer*\n**view-server**`\")\nViewServer:view-server:SecretStoreEndpoint(\"`*Endpoint*\n**view-server secret store endpoint**`\")\nViewServer:view-server:SecretsStoreConnection(\"`*Connection*\n**view-server secrets store connection**`\")\nViewServer:view-server:Endpoint(\"`*Endpoint*\n**view-server endpoint**`\")\nViewServer:view-server:OpenMetadataandGovernanceEndUserAPIs(\"`*APIManager*\n**Open Metadata and Governance End User APIs**`\")\nViewServer:view-server:Connection(\"`*VirtualConnection*\n**view-server connection**`\")\nViewServer:view-server-->|SupportedSoftwareCapability|ViewServer:view-server:OpenMetadataandGovernanceEndUserAPIs\nViewServer:view-server:SecretsStoreConnection-->|ConnectionConnectorType|Egeria:SecretsStoreConnector:YAMLFile\nViewServer:view-server:Connection-->|ConnectionToAsset|ViewServer:view-server\nViewServer:view-server-->|ServerEndpoint|ViewServer:view-server:Endpoint\nViewServer:view-server:Connection-->|EmbeddedConnection|ViewServer:view-server:SecretsStoreConnection\nViewServer:view-server-->|SourcedFrom|ViewServer:serverName\nViewServer:view-server-->|DeployedOn|OMAGServerPlatform:DefaultLocalOMAGServerPlatform\nViewServer:view-server:Endpoint-->|ConnectionEndpoint|ViewServer:view-server:Connection\nViewServer:view-server:Connection-->|ConnectionConnectorType|Egeria:ResourceConnector:System:ViewServer\nViewServer:view-server:SecretStoreEndpoint-->|ConnectionEndpoint|ViewServer:view-server:SecretsStoreConnection\n"

... which is returned in the getAssetGraph() response like this(go to end):

{
  "class": "AssetGraphResponse",
  "relatedHTTPCode": 200,
  "assetGraph": {
    "properties": {
      "class": "AssetProperties",
      "typeName": "SoftwareServer",
      "qualifiedName": "View Server:view-server",
      "displayName": "view-server",
      "displayDescription": "A server that supplies REST API endpoints for User Interfaces and non-Java environments such as Python.",
      "name": "view-server",
      "resourceName": "view-server",
      "versionIdentifier": "Egeria OMAG Server Platform (version 5.2-SNAPSHOT)\n",
      "resourceDescription": "A server that supplies REST API endpoints for User Interfaces and non-Java environments such as Python.",
      "deployedImplementationType": "View Server"
    },
    "elementHeader": {
    },
    "anchoredElements": [...],
   "relationships":[...],
    "mermaidGraph": "---\ntitle: Asset - view-server [5ae81670-0710-45b7-94bf-6337871b7dc1]\n---\nflowchart LR\n%%{init: {\"flowchart\": {\"htmlLabels\": false}} }%%\n\nViewServer:view-server(\"`*SoftwareServer*\n**view-server**`\")\nViewServer:view-server:SecretStoreEndpoint(\"`*Endpoint*\n**view-server secret store endpoint**`\")\nViewServer:view-server:SecretsStoreConnection(\"`*Connection*\n**view-server secrets store connection**`\")\nViewServer:view-server:Endpoint(\"`*Endpoint*\n**view-server endpoint**`\")\nViewServer:view-server:OpenMetadataandGovernanceEndUserAPIs(\"`*APIManager*\n**Open Metadata and Governance End User APIs**`\")\nViewServer:view-server:Connection(\"`*VirtualConnection*\n**view-server connection**`\")\nViewServer:view-server-->|SupportedSoftwareCapability|ViewServer:view-server:OpenMetadataandGovernanceEndUserAPIs\nViewServer:view-server:SecretsStoreConnection-->|ConnectionConnectorType|Egeria:SecretsStoreConnector:YAMLFile\nViewServer:view-server:Connection-->|ConnectionToAsset|ViewServer:view-server\nViewServer:view-server-->|ServerEndpoint|ViewServer:view-server:Endpoint\nViewServer:view-server:Connection-->|EmbeddedConnection|ViewServer:view-server:SecretsStoreConnection\nViewServer:view-server-->|SourcedFrom|ViewServer:serverName\nViewServer:view-server-->|DeployedOn|OMAGServerPlatform:DefaultLocalOMAGServerPlatform\nViewServer:view-server:Endpoint-->|ConnectionEndpoint|ViewServer:view-server:Connection\nViewServer:view-server:Connection-->|ConnectionConnectorType|Egeria:ResourceConnector:System:ViewServer\nViewServer:view-server:SecretStoreEndpoint-->|ConnectionEndpoint|ViewServer:view-server:SecretsStoreConnection\n"
  }
}

Related Issue(s)

None

Testing

Simple testing at this stage

Release Notes & Documentation

One we are happy with the rendering, this will go in the Asset Catalog OMVS documentation. Other OMVSs are likely to have similar extensions.

Additional notes

None