Tie the Zed application ID to the release channel (#11335)

Since we do want to have different versions of Zed running on the same
Linux install, we need to give them different application IDs so they're
not grouped together as the same application.

This changes the app_id depending on the releaes channel and, crucially,
it also matches them up with the bundle identifiers that we use on
macOS.

Release Notes:

- N/A