feat(front): connect download report to backend

Added functionality to download a report from the db, as well as a postman script to test for report downloading.

Has been tested with a placeholder json.

Should ideally be formatted at some point in the future.

Steps to test:

• Add a report in the report table by writing something in the "report_content", seen in the image below:

• Go to a unit, such as http://127.0.0.1:5173/courseview/fall2023/TDT4100/unit1/report

• Press download and a file should be downloaded, containing the report from the unit.

Co-authored-by: Ulrik Isdahl ulrikyi@stud.ntnu.no

Closes #62 (closed)