Feature: two-factor authentication

[shamoon]

Proposed change

This pretty much entirely uses allauth's handling of totp and just kinda connects it to our frontend.

Closes #424

Type of change

• Bug fix: non-breaking change which fixes an issue.
• New feature / Enhancement: non-breaking change which adds functionality. Please read the important note above.
• Breaking change: fix or feature that would cause existing functionality to not work as expected.
• Documentation only.
• Other. Please explain:

Checklist:

• I have read & agree with the contributing guidelines.
• If applicable, I have included testing coverage for new code in this PR, for backend and / or front-end changes.
• If applicable, I have tested my code for new features & regressions on both mobile & desktop devices, using the latest version of major browsers.
• If applicable, I have checked that all tests pass, see documentation.
• I have run all pre-commit hooks, see documentation.
• I have made corresponding changes to the documentation as needed.
• I have checked my modifications for any breaking changes.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.52%. Comparing base (36ecb85) to head (f80e85e).

Additional details and impacted files

@@            Coverage Diff             @@
##              dev    #8012      +/-   ##
==========================================
+ Coverage   97.50%   97.52%   +0.01%     
==========================================
  Files         475      475              
  Lines       19866    20006     +140     
  Branches     1564     1644      +80     
==========================================
+ Hits        19370    19510     +140     
+ Misses        496      493       -3     
- Partials        0        3       +3     

Flag	Coverage Δ
backend	96.40% <100.00%> (+0.02%)	⬆️
frontend	98.76% <100.00%> (+0.01%)	⬆️

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[chwiese]

Thank you for working on this @shamoon. I saw that allauth supports WebAuthn (Passkeys) for MFA. Would you consider supporting that in addition to TOTP please?

[stumpylog]

Need to test it out too, but a couple minor thoughts