fix(desktop): toggle maximizing window with double click on mac

[shanebishop1]

What does this PR do?

Fixes #9167

Simple change that allows Mac users to double-click to maximize the window by detecting double-clicks in the title bar (and adding allow-toggle-maximize capability to the Tauri capabilities config).

This fix only works once the window has actually fully initialized, but this was a pre-existing issue that also prevents the user from re-positioning the window by dragging while the initialization is happening. I think this would also be nice to look at but feels out-of-scope for this quick fix. Also, this change only addresses the issue on Mac.

Before fix:

https://github.com/user-attachments/assets/167bebb5-54fe-48da-b5ab-c6a49bf61e7c

After fix:

https://github.com/user-attachments/assets/44ba8778-b903-47ac-9b8a-0873ede37797

How did you verify your code works?

Tested the fix locally on my Mac and made sure that lint/typecheck/tests passed