Move Application state to service package

javadoc/NTNU/IDATT1002/ApplicationState.html

src/main/java/NTNU/IDATT1002/controllers/CreateAlbum.java

src/main/java/NTNU/IDATT1002/controllers/UploadImages.java

src/main/java/NTNU/IDATT1002/service/ApplicationState.java

src/main/java/NTNU/IDATT1002/service/UserService.java