Add ability to attach Copilot window only to Xcode projects/workspaces, ignoring standalone files

[Alkenso]

Now settings allows to enable/disable Copilot window to auto-track and attach to Xcode window
Feature is great but lacks ability to attach Copilot only to Xcode projects, ignoring random files opened by Xcode (JSONs, settings files, etc).

Please take a look at proposal of new Auto-attach Chat Window to Xcode setting:
cb32356