[Core] Created non-templated response schemas to support versioning

[widal001]

Summary

Problem: When TypeSpec models have templates (e.g. Ok<T> or Paginated<T>) they don't get emitted as JSON schemas by TypeSpec. This makes it hard to document changes to those fields, like #959, in our schema changelog and generate the correct documentation for them.

Recommendation: The CommonBenefits core library demonstrates how to solve this problem using a combination of base, templated, and non-templated schemas to solve this problem by:

• Keeping the properties of these templated and non-templated schemas stay in sync
• Enabling maintainers to generate new schemas from these templates: Responses.PaginatedT<Models.ProgramBase>
• Generating JSON schemas for these base response schemas

Examples

• Ok response doesn't need a base schema
• Paginated schema does require a base schema

Acceptance criteria

• These base response schemas (e.g. Ok, Paginated, Filtered, etc.) now have JSON schemas generated for them
• These base response schemas have been added to the website docs for responses with versioning, starting with the version in which their templated equivalent was added (so v0.1.0 for most)
• The templated versions of these schemas are now suffixed with T (e.g. OkT) and are still used to generate response bodies for the routes
• The approach to implementing this either closely matches the CommonBenefits protocol, or the PR explains why an easier option exists (e.g. TypeSpec now supports this natively through tsconfig.json -- though I don't think they do at the moment)