Implement log file

[logancyang]

Right now user has to

• toggle on debug mode in Copilot settings under advanced tab
• turn off other noisy plugins
• open the dev console
• perform the action in copilot chat
• provide the screenshot of the chat and console

This is quite tedious and may not offer a good view of the issue.

There should be a log file that has all the relevant logs from logInfo and logError, and the full serialized chat.

Bonus: The log file should be easily readable by AI.