Feat: Two-factor authentication

[lewislarsen]

Pull Request

Description

This Pull Requests adds two-factor-authentication support to Vanguard, the idea was a system similar to GitHub's and this is very much an initial implementation of the feature, eventually I would like to add more methods, but presently it only supports traditional app 6-digit-code auth.

This implementation also has email notifications for critical actions, such as enabling/disabling two-factor and so on.

Closes #21

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

• Automated testing (Feature tests, Unit tests)
• Manual testing

Checklist:

• I have performed a self-review of my own code
• My changes do not introduce any new warnings or errors
• I have added tests that prove my fix is effective or that my feature works
• New and existing tests pass locally with my changes
• I have used translation helpers and provided translations (where appropriate)

Screenshots (if applicable):

Here are a few screenshots of the feature so far.

Additional context

I have only added traditional app two-factor-authentication at this point, adding passkeys etc would be too much for this PR.