feat(openapi): implement spec operation parser and auth handler (part 2)

[AmaadMartin]

Link to Issue or Description of Change

Problem:
Generating LLM-callable tools from OpenAPI specifications requires robust parsing of spec parameters and managing authentication requirements within session state.

Solution:
Implemented OpenAPI spec operation parsing and tool auth handling (Part 2 of 4):

• operation_parser.ts: Logic to extract and parse API parameters, request body schemas, and response types from OpenAPI path operations.
• openapi_spec_parser.ts: Base OpenAPI spec parsing logic including sanitizeSchemaTypes to ensure compatibility with Gemini function calling schemas.
• tool_auth_handler.ts: Context credential caching and preparation handler for tool contexts.

Testing Plan

Unit Tests:

• I have added or updated unit tests for my change.
• All unit tests pass locally.

Summary of passed results:

• Added unit tests for parsing operations, sanitizing schemas, and tool auth handling.
• Actual Line Coverage by File:
  • openapi_spec_parser/tool_auth_handler.ts: 100%
  • openapi_spec_parser/openapi_spec_parser.ts: 94.81%
  • openapi_spec_parser/operation_parser.ts: 93.60%

Checklist

• I have performed a self-review of my own code.
• I have added tests that prove my fix is effective or that my feature works.
• New and existing unit tests pass locally with my changes.