WIP: Feat: Add Code Execution button for gemini only

[ous50]

also Fix: defaultPaintingProvider type error in migrate 170 and 171

Documentation from Google: https://ai.google.dev/gemini-api/docs/code-execution#enable-code-execution

What this PR does

Before this PR: cannot use Gemini's codeExecution tool.

After this PR: can use Gemini's codeExecution tool.

Fixes #

Why we need it and why it was done in this way

The following tradeoffs were made: I have to make a new chunk block type specifically for rendering part.executableCode.code and part.codeExecutionResult.output

The following alternatives were considered:

Links to places where the discussion took place:

Breaking changes

If this PR introduces breaking changes, please describe the changes and the impact on users.

1. Users would have found a new button when using Gemini models in inputBarTool.
2. New chunk type introduced and may have some glich(specifically, repeat request) while alpha testing.

Special notes for your reviewer

Checklist

This checklist is not enforcing, but it's a reminder of items that could be relevant to every PR.
Approvers are expected to review this list.

• PR: The PR description is expressive enough and will help future contributors
• Code: Write code that humans can understand and Keep it simple
• Refactor: You have left the code cleaner than you found it (Boy Scout Rule)
• Upgrade: Impact of this change on upgrade flows was considered and addressed if required
• Documentation: A user-guide update was considered and is present (link) or not required. You want a user-guide update if it's a user facing feature.

Release note