Migrate permissions to account type

[itsthejoker]

Relevant issue: #14

Description:

As expected, this is very much not a small thing. This PR moves all permissions and appropriate flags to the account_type attribute behind the user model, which django doesn't particularly like but works better usability-wise for our application.

This is still unfinished, so opening as a draft.

Checklist:

• [ ] Code Quality
• [ ] Pep-8
• [ ] Tests (if applicable)
• [ ] Success Criteria Met
• [ ] Inline Documentation
• [ ] Wiki Documentation (if applicable)

[github-actions[bot]]

Current coverage: 71%