Feature/savefiles

[Aqua-sc]

In this PR:

• added persistent directory to the spring container
• changed the max requestsize for a file to 10MB (subject to change, just chosen randomly)
• added some missing @GeneratedValue annotations to GroupEntity and SubmissionEntity
• created Filehandler class with static method to:
  • Save a submission
  • Get a submission
• created 2 functional routes. Mostly to demonstrate the usage of the filehandler but both of those should be fully functional apart from using the id of the current user. These can be added to the correct controllers :
  • route /project/{projectid}/submit (to submit a file)
  • submissions/{submissionid} (to fetch a file)

To test the submit route a curl-request can be used, e.g (replace the file path ofcourse)i:

 curl --request POST \
 --url http://localhost:8080/project/1/submit \
 --header 'Content-Type: multipart/form-data' \
 --form 'submissionTime=2024-03-06 12:30:00.123456789' \
 --form 'file=@/mnt/c/Users/aqua/Downloads/b89fe448-4bbd-4416-9ab3-ff1e24fefb07_Export-c724ab27-cf83-482c-92bf-64faa9e6dcb5.zip'

I also check if its a zip file but this doesn't have a 100% succes rate as a Word file get detected as zip (because it technically is).
Checking file extension in this case also didn't work as due to the upload (or perhaps the way I sent my request) it got automatically packed inside a zip file

[Matthias-VE]

Looks good!