Fix ReferenceManyField throws error after insert

[fzaninotto]

This fixes a nasty bug that is hard to reproduce.

The bug occurs when a ReferenceManyField renders a second time after the reference data has been updated on the server-side, and if the children of the ReferencenceManyField don't work with an empty record. This causes a "Something Went Wrong" screen in production.

A more specific bug repro:

• in PostEdit, change the final tab to

            <FormTab label="post.form.comments">
                <ReferenceManyField
                    reference="comments"
                    target="post_id"
                    addLabel={false}
                    fullWidth
                    perPage={2}
                >
                    <Datagrid>
                        <FooField label="foo" />
                    </Datagrid>
                </ReferenceManyField>
            </FormTab>

with

// this will fail if record is undefined
const FooField = ({ record }) => <span>{record.foo}</span>;

• go to posts list
• click on edit post 2
• go to comment list
• create 2 new comments on post 2
• go to posts list
• click on edit post 2
• error

The cause is a lack of synchronization between the ids and the data in useGetManyReference, due to two Redux selectors working on one another (i.e. one after the other).

The fix is similar to #5577 on useGetList: we don't execute one selector after another, we execute them both at the same time.