Refactor/add nav bar base controller

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

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

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

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

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

...ain/java/NTNU/IDATT1002/controllers/NavBarController.java

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

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

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

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

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

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

src/main/resources/NTNU/IDATT1002/create_album.fxml

src/main/resources/NTNU/IDATT1002/explore.fxml

src/main/resources/NTNU/IDATT1002/explore_albums.fxml

src/main/resources/NTNU/IDATT1002/main.fxml

src/main/resources/NTNU/IDATT1002/map.fxml

src/main/resources/NTNU/IDATT1002/search.fxml

src/main/resources/NTNU/IDATT1002/search_results.fxml

src/main/resources/NTNU/IDATT1002/upload.fxml