fix(editor): allow create_file tool to accept content argument

[rayysidd]

What does this PR do?

Updates the Editor.create_file method to accept an optional content argument.

Why is this change necessary?

Fixes #1920

When LLMs (like Gemini or GPT-4) use the Editor.create_file tool, they frequently attempt to pass a content or text argument to write data immediately upon creation. The current implementation rejects these arguments with a TypeError, causing agents to crash or fail to save generated work.

How to verify

1. Run a Data Interpreter agent with a task that requires saving a file.
2. Observe that the agent attempts to call create_file(filename="...", content="...").
3. Verify the file is created successfully with the content, instead of throwing a TypeError.