Big rework + Notifications API

[bigcat88]

Related to this: nextcloud/app_api#25

CI will fail until merge in AppEcosystem, that's fine

Added Notification API + start grouping APIs

[codecov]

Codecov Report

Merging #59 (dab149d) into main (f149e52) will increase coverage by 0.07%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main      #59      +/-   ##
==========================================
+ Coverage   98.87%   98.95%   +0.07%     
==========================================
  Files          21       24       +3     
  Lines        1421     1525     +104     
==========================================
+ Hits         1405     1509     +104     
  Misses         16       16              

Files Changed	Coverage Δ
nc_py_api/_session.py	97.95% <ø> (ø)
nc_py_api/apps.py	100.00% <ø> (ø)
nc_py_api/preferences.py	100.00% <ø> (ø)
nc_py_api/theming.py	100.00% <ø> (ø)
nc_py_api/__init__.py	100.00% <100.00%> (ø)
nc_py_api/_version.py	100.00% <100.00%> (ø)
nc_py_api/constants.py	100.00% <100.00%> (ø)
nc_py_api/files.py	98.90% <100.00%> (-0.28%)	⬇️
nc_py_api/files_defs.py	100.00% <100.00%> (ø)
nc_py_api/files_sharing.py	80.48% <100.00%> (-7.92%)	⬇️
... and 9 more