Improve the @requestBody

[jannyHou]

Suggestion

A follow-up story for #2654

Use Cases

Implement @requestBody(spec, model, schemaOptions) as the new requestBody decorator.

Examples

See the Create endpoint and Update endpoint.

Acceptance criteria

• Modify the current @requestBody() according to the spike code, pass
  existing tests across all repos.
• Add more unit tests to verify all the signatures.
• Fix the type conflict detect, see test case 'catches type conflict', and
  discussion in
  comment

[stale]

This issue has been marked stale because it has not seen activity within six months. If you believe this to be in error, please contact one of the code owners, listed in the CODEOWNERS file at the top-level of this repository. This issue will be closed within 30 days of being stale.

[stale]

This issue has been closed due to continued inactivity. Thank you for your understanding. If you believe this to be in error, please contact one of the code owners, listed in the CODEOWNERS file at the top-level of this repository.