SDK management

Marked forked SDK versions with a *.
Classified SDKs as global and gave them priority.
Implemented automatic registration of any unregistered SDK or west workspaces.
Improved the menu for switching manifests with the ability to detect manifests with different self.path.
Allowed users to create manifests when manifest repo does not have a remote.
Fixed UI not updating when the last SDK is removed.
Fixed west workspace detection.
Fixed fork detection.