REST plugin stores the path of the Activator class instead of the classname in the project config

The fully qualified path aka location of the file containing the @ApplicationPath annotation is stored in the project configuration by the REST plugin. It should instead store just the simple class name since this class name is appended with the stored package name to determine whether the facet should be activated or not.

There are no issues encountered except that the ApplicationPath class is scanned for every time the project is opened since the class will eventually be found, but once found the incorrect entry is stored.