Take kausal_common mutations for registering/deleting users into use

[bbliem]

This requires kausaltech/kausal-backend-common#35

[kausal-code-coverage]

Codecov Report

Attention: Patch coverage is 60.00000% with 18 lines in your changes missing coverage. Please review.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
paths/schema_test_mode.py	0.00%	12 Missing ⚠️
users/schema.py	76.92%	6 Missing ⚠️

@@            Coverage Diff             @@
##             main     #119      +/-   ##
==========================================
- Coverage   41.55%   41.54%   -0.01%     
==========================================
  Files         208      209       +1     
  Lines       24231    24254      +23     
  Branches     3568     3568              
==========================================
+ Hits        10069    10077       +8     
- Misses      13345    13363      +18     
+ Partials      817      814       -3     

Flag	Coverage Δ
e2e-tests	14.34% <0.00%> (-0.02%)	⬇️
unittests	33.83% <60.00%> (+<0.01%)	⬆️

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Files with missing lines	Coverage Δ
paths/schema.py	81.15% <100.00%> (+3.82%)	⬆️
users/schema.py	72.72% <76.92%> (-2.28%)	⬇️
paths/schema_test_mode.py	0.00% <0.00%> (ø)

... and 2 files with indirect coverage changes