feat(types): build uniontypes too

[mttrbrts]

Modifies the build step to also build an alternative set of Typescript type definitions that use static union types for field declarations where type inheritance is used.

Changes

• Uses the new flattenSubclassesToUnion on the TypeScript codegen visitor
• Exposes the types in two new root exports:

import { concertoMetamodelWithUnions, concertoWithUnions } from '@accordproject/concerto-types';

const position: concertoMetamodelWithUnions.IPosition = { 
//...
};

Flags

• Note that because this is a static build step, users of the new types will not be able to validate against custom extensions to the base types in client-code. However, the impact is muted here, because client extensions to the metamodel are not encouraged.

Related Issues

• feat(ts): add flattenSubclassesToUnion param concerto-codegen#78

Author Checklist

• Ensure you provide a DCO sign-off for your commits using the --signoff option of git commit.
• Vital features and changes captured in unit and/or integration tests
• Commits messages follow AP format
• Extend the documentation, if necessary
• Merging to main from fork:branchname

[dselman]

Great job with the e2e test.

[dselman]

Need to exclude generated code from license check:

No default format specified using {"prepend":"/*","append":"*/"} as backup
✗ License not found in  /home/runner/work/concerto/concerto/packages/concerto-types/src/concerto.metamodel.test.ts
✗ License not found in  /home/runner/work/concerto/concerto/packages/concerto-types/src/generated/unions/[email protected]
✗ License not found in  /home/runner/work/concerto/concerto/packages/concerto-types/src/generated/unions/concerto.ts
✗ License not found in  /home/runner/work/concerto/concerto/packages/concerto-types/src/generated/unions/[email protected]