changed design, added levelPackSelectGUI (partial)

bin/de/bricked/resources/levelpacks/default.json

bin/de/bricked/ui/LevelPackSelectGUI.fxml

bin/de/bricked/ui/LevelSelectGUI.fxml

src/de/bricked/commandLine/commands/CommandBundle.java

src/de/bricked/game/levels/LevelPackHandler.java

src/de/bricked/game/levels/LevelPackReader.java

src/de/bricked/main/Main.java

src/de/bricked/resources/levelpacks/default.json

src/de/bricked/ui/Controller.java

src/de/bricked/ui/CustomListView.java

src/de/bricked/ui/LevelCell.java

src/de/bricked/ui/LevelPackCell.java

src/de/bricked/ui/LevelPackSelectController.java

src/de/bricked/ui/LevelPackSelectGUI.fxml

src/de/bricked/ui/LevelSelectController.java

src/de/bricked/ui/LevelSelectGUI.fxml