Add Project Remove Listener, mark old listener classes as deprecated

...tobias/playpad/server/server/project/ProjectHandler.scala

...erver/server/project/listener/CollectionAddListener.scala

...er/server/project/listener/CollectionRemoveListener.scala

...ias/playpad/server/server/project/listener/Listener.scala

...rver/server/project/listener/PropertyUpdateListener.scala

...aypad/server/server/project/sync/ProjectSyncHandler.scala

...project/sync/listener/project/ProjectRemoveListener.scala