### What problem does this PR solve?
- Add comprehensive test suite for chunk operations including:
- Test files for create, list, retrieve, update, and delete chunks
- Authorization tests
- Batch operations tests
- Update test configurations and common utilities
- Validate `important_kwd` and `question_kwd` fields are lists in
chunk_app.py
- Reorganize imports and clean up duplicate code
### Type of change
- [x] Add test cases
Test: Refactor test fixtures to use HttpApiAuth naming consistently (#8180)
### What problem does this PR solve?
- Rename `api_key` fixture to `HttpApiAuth` across all test files
- Update all dependent fixtures and test cases to use new naming
- Maintain same functionality while improving naming clarity
The rename better reflects the fixture's purpose as an HTTP API
authentication helper rather than just an API key.
### Type of change
- [x] Refactoring
Test: Refactor test fixtures and add SDK session management tests (#8141)
### What problem does this PR solve?
- Consolidate HTTP API test fixtures using batch operations
(batch_add_chunks, batch_create_chat_assistants)
- Fix fixture initialization order in clear_session_with_chat_assistants
- Add new SDK API test suite for session management
(create/delete/list/update)
### Type of change
- [x] Add test cases
- [x] Refactoring
Test: Added test cases for Delete Chunks HTTP API (#6612)
### What problem does this PR solve?
_Briefly describe what this PR aims to solve. Include background context
that will help reviewers understand the purpose of the PR._
### Type of change
- [x] add test cases
Test: Update test cases to reduce execution time (#6470)
### What problem does this PR solve?
_Briefly describe what this PR aims to solve. Include background context
that will help reviewers understand the purpose of the PR._
### Type of change
- [x] update test cases
Liu An