File ownership and ACL blocking

[ARMmaster17]

Summary

• Added owner attribute to FileEntity objects.
• Added business logic that only allows for people to read and delete their own files.
• Added business logic for anyone to read and delete public files (i.e. files with no owner).

Closes #148

How to Test

• Verify that all JUnit tests pass.
• Implement file upload/access in a controller and verify that users can only interact with their own files.

Comments

Not included in this PR is the logic for doctors to access files uploaded by their patients. This will be addressed in a separate PR as there is some common logic that needs to be shared with other features. Also not included is a file listing using this ACL system.

[github-actions[bot]]

Unit Test Results

12 files  ±0  12 suites  ±0   15s :stopwatch: +2s 50 tests +3  50 :heavy_check_mark: +3  0 :zzz: ±0  0 :x: ±0 

Results for commit 26230dea. ± Comparison against base commit bf1217eb.

This pull request removes 2 and adds 5 tests. Note that renamed tests count towards both.

``` com.virtudoc.web.FileServiceTest ‑ CreatesFile com.virtudoc.web.FileServiceTest ‑ ReadFile ``` ``` com.virtudoc.web.FileServiceTest ‑ CreatesPublicFile com.virtudoc.web.FileServiceTest ‑ NonOwnerCannotReadPrivateFile com.virtudoc.web.FileServiceTest ‑ PublicCannotReadPrivateFile com.virtudoc.web.FileServiceTest ‑ ReadPrivateFile com.virtudoc.web.FileServiceTest ‑ ReadPublicFile ```

:recycle: This comment has been updated with latest results.