Tags at upload

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

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

src/main/java/NTNU/IDATT1002/repository/TagRepository.java

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

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