Remove django-allauth-2fa

[matmair]

This PR remove django-allauth-2fa and replaces it with the inline functions of django-allauth. This reduces the depenecdy footprint and sets us up for further improvements that are planned upstream. Those will reduce the dependency footprint even more and close #4002

Closes #6281

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[codecov[bot]]

Codecov Report

Attention: Patch coverage is 61.53846% with 20 lines in your changes missing coverage. Please review.

Project coverage is 85.53%. Comparing base (c9e9ef1) to head (843fdc9). Report is 6 commits behind head on master.

:exclamation: Current head 843fdc9 differs from pull request most recent head 8fad7b1

Please upload reports for the commit 8fad7b1 to get more accurate results.

Files	Patch %	Lines
src/backend/InvenTree/users/test_migrations.py	27.77%	13 Missing :warning:
...users/migrations/0012_migrate_mfa_20240408_1659.py	66.66%	7 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6293      +/-   ##
==========================================
+ Coverage   84.10%   85.53%   +1.42%     
==========================================
  Files        1066      900     -166     
  Lines       46662    41227    -5435     
  Branches     1396      325    -1071     
==========================================
- Hits        39244    35262    -3982     
+ Misses       7055     5927    -1128     
+ Partials      363       38     -325     

Flag	Coverage Δ
backend	85.23% <61.53%> (-0.10%)	:arrow_down:
migrations	42.48% <61.53%> (-0.01%)	:arrow_down:
pui	44.03% <ø> (-21.46%)	:arrow_down:

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[matmair]

Upstream is not supporting enforced MFA right now - postboning to 0.16.0

[matmair]

OK MFA enforcing can be build by us and upstreamed but https://github.com/pennersr/django-allauth/issues/3830 is a new blocking

[matmair]

Site-Note: It seems I always end up ripping out/replacing the features I write