#36020 feat: Add OpenAPI Support to chat.pinMessage API

Description:
This PR integrates OpenAPI support into the Rocket.Chat API, migrate of Rocket.Chat API endpoints to the new OpenAPI pattern. The update includes improved API documentation, enhanced type safety, and response validation using AJV.

Key Changes:

• Implemented the new pattern and added AJV-based JSON schema validation for API.
• Uses the ExtractRoutesFromAPI utility from the TypeScript definitions to dynamically derive the routes from the endpoint specifications.
• Enabled Swagger UI integration for this API.
• This does not introduce any breaking changes to the endpoint logic.

Issue Reference:
Relates to #34983, part of the ongoing OpenAPI integration effort.

Testing:

• Verified that the API response schemas are correctly documented in Swagger UI.

• All tests passed without any breaking changes

Endpoint:

• Pin Message

  

Looking forward to your feedback! 🚀