Support for SU from Python

[JulianGodd]

A Django app I'm working on surfaced the need to SU directly from python. Unfortunately, as Django doesn't support redirecting with POST and django-su's login_as_user view only allows POST requests, this isn't possible.

To enable this I moved a majority of the login_as_user function to a new function: su_in in utils.

This enables apps using django-su to optionally SU users without requiring logging in through Django's Admin app.

I chose this over allowing GET requests to login_as_user since that seemed to have security implications and made redirecting back to the original page more janky.

[coveralls]

coverage: 93.312% (-1.1%) from 94.426% when pulling 46882fa on JulianGodd:develop into aadabf6 on adamcharnock:develop.

[JulianGodd]

The error common to all 3 failing tests occurs when github actions uses typing_extensions version 4.8 which drops support for python 3.7.

  File "/opt/hostedtoolcache/Python/3.7.17/x64/lib/python3.7/site-packages/typing_extensions-4.8.0-py3.7.egg/typing_extensions.py", line 874
    def TypedDict(typename, fields=_marker, /, *, total=True, **kwargs):
                                            ^
SyntaxError: invalid syntax

The error on the / character is for positional only arguments, a feature added in python 3.8

These errors are independent of django-su and not introduced by my pull request (no django-su code appears in the stack trace).

Thanks

[codecov-commenter]

Codecov Report

Attention: 3 lines in your changes are missing coverage. Please review.

Comparison is base (aadabf6) 94.46% compared to head (46882fa) 93.31%.

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop      #84      +/-   ##
===========================================
- Coverage    94.46%   93.31%   -1.16%     
===========================================
  Files            9        9              
  Lines          307      314       +7     
===========================================
+ Hits           290      293       +3     
- Misses          17       21       +4     

Files	Coverage Δ
django_su/views.py	90.24% <100.00%> (-0.50%)	⬇️
django_su/utils.py	87.80% <85.00%> (-2.68%)	⬇️

... and 1 file with indirect coverage changes

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[JulianGodd]

Can you rerun the github action? All of my changes since originally making the pull request have been to the github actions and automated testing. I've verified that they succeed on my fork.