Add button to service app menu to open Copilot for Xcode app [ENHANCEMENT]

[KieranConlon]

Suggestion to simplify access to the Copilot for Xcode.app by adding a "Open Copilot for Xcode" option to the service app's menu bar.

Equivalent to running:

open "/Applications/Copilot for Xcode.app"

Mock-up of new menu...