Refactor project related classes

...t/sync/listener/pad/settings/PadSettingsAddListener.scala

...ync/listener/pad/settings/PadSettingsUpdateListener.scala

...r/server/project/sync/listener/page/PageAddListener.scala

...erver/project/sync/listener/page/PageRemoveListener.scala

...erver/project/sync/listener/page/PageUpdateListener.scala

...r/server/project/sync/listener/path/PathAddListener.scala

...erver/project/sync/listener/path/PathRemoveListener.scala

...er/project/sync/listener/project/ProjectAddListener.scala

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

...project/sync/listener/project/ProjectUpdateListener.scala

src/main/scala/de/tobias/playpad/server/sql/SqlDef.scala

...la/de/tobias/playpad/server/sql/loader/DesignLoader.scala

...scala/de/tobias/playpad/server/sql/loader/PadLoader.scala

...cala/de/tobias/playpad/server/sql/loader/PageLoader.scala

...cala/de/tobias/playpad/server/sql/loader/PathLoader.scala

...a/de/tobias/playpad/server/sql/loader/ProjectLoader.scala

...cala/de/tobias/playpad/server/sql/saver/DesignSaver.scala

...n/scala/de/tobias/playpad/server/sql/saver/PadSaver.scala

.../scala/de/tobias/playpad/server/sql/saver/PageSaver.scala

.../scala/de/tobias/playpad/server/sql/saver/PathSaver.scala