fix: Fix/azure native tool calls from main

[AbhimanyuAryan]

This pull request updates the Azure OpenAI backend to improve how tool calls are handled and streamed. The main change is that tool calls are now accumulated and yielded as structured tool_calls chunks, rather than being ignored or treated as plain content. This results in more accurate and structured streaming of tool call information to downstream consumers.

Tool Call Streaming Improvements:

• Tool calls are now accumulated during streaming and yielded as structured tool_calls chunks, rather than being ignored or appended as plain content. This allows downstream consumers to process tool calls more reliably. [1] [2] [3]
• The function _convert_chunk_to_stream_chunk now emits tool_calls chunks when tool calls are present, instead of flattening them into content.

Code Simplification and API Alignment:

• The preparation of messages with workflow tool instructions is removed, as tools are now passed natively to the API and messages are used as-is.
• The streaming loop is updated to accumulate both content and tool call deltas, ensuring that all tool call information is captured and yielded after streaming completes. [1] [2] [3]## PR Title Format
  Your PR title must follow the format: <type>: <brief description>

Valid types:

• fix: - Bug fixes
• feat: - New features
• breaking: - Breaking changes
• docs: - Documentation updates
• refactor: - Code refactoring
• test: - Test additions/modifications
• chore: - Maintenance tasks
• perf: - Performance improvements
• style: - Code style changes
• ci: - CI/CD configuration changes

Examples:

• fix: resolve memory leak in data processing
• feat: add export to CSV functionality
• breaking: change API response format
• docs: update installation guide

Description

Brief description of the changes in this PR

Type of change

• Bug fix (fix:) - Non-breaking change which fixes an issue
• New feature (feat:) - Non-breaking change which adds functionality
• Breaking change (breaking:) - Fix or feature that would cause existing functionality to not work as expected
• Documentation (docs:) - Documentation updates
• Code refactoring (refactor:) - Code changes that neither fix a bug nor add a feature
• Tests (test:) - Adding missing tests or correcting existing tests
• Chore (chore:) - Maintenance tasks, dependency updates, etc.
• Performance improvement (perf:) - Code changes that improve performance
• Code style (style:) - Changes that do not affect the meaning of the code (formatting, missing semi-colons, etc.)
• CI/CD (ci:) - Changes to CI/CD configuration files and scripts

Checklist

• I have run pre-commit on my changed files and all checks pass
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• 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

Pre-commit status

# Paste the output of running pre-commit on your changed files:
# uv run pre-commit install
# git diff --name-only HEAD~1 | xargs uv run pre-commit run --files # for last commit
# git diff --name-only origin/<base branch>...HEAD | xargs uv run pre-commit run --files # for all commits in PR
# git add <your file> # if any fixes were applied
# git commit -m "chore: apply pre-commit fixes"
# git push origin <branch-name>

How to Test

Add test method for this PR.

Test CLI Command

Write down the test bash command. If there is pre-requests, please emphasize.

Expected Results

Description/screenshots of expected results.

Additional context

Add any other context about the PR here.