Delete scanreport backend

[Dev-Akashili]

Changes

Closes #729

• Added delete method to the scanreport v2 endpoint.
• Added method to delete scan report and data dictionary files in blob storage.

Checks

Important: please complete these before merging.

• [x] Run migrations, if any.
• [x] Update changelog.md, including migration instructions if any.
• [x] Run unit tests.

[github-actions[bot]]

Tests	Skipped	Failures	Errors	Time
25	1 :zzz:	1 :x:	0 :fire:	4.312s :stopwatch:

[github-actions[bot]]

Tests	Skipped	Failures	Errors	Time
25	1 :zzz:	1 :x:	0 :fire:	4.240s :stopwatch: