initial commit for future SharesAPI

[bigcat88]

Before developing sharing api, need to implement bridge between shares permissions which is int and filesystem permissions which type is str, so it is first task.

• Unify FilesAPI and SharesAPI permissions
• Implement creating, deleting, listing SharesAPI
• Wrote tests for creating, deleting, listing SharesAPI
• Wrote docstrings for what parameters mean in each method.

[codecov]

Codecov Report

Merging #42 (33c30de) into main (e3c5b80) will decrease coverage by 2.06%.
The diff coverage is 81.11%.

@@            Coverage Diff             @@
##             main      #42      +/-   ##
==========================================
- Coverage   97.97%   95.92%   -2.06%     
==========================================
  Files          19       20       +1     
  Lines        1134     1275     +141     
==========================================
+ Hits         1111     1223     +112     
- Misses         23       52      +29     

Impacted Files	Coverage Δ
nc_py_api/users_status.py	100.00% <ø> (ø)
nc_py_api/weather_status.py	100.00% <ø> (ø)
nc_py_api/files.py	93.13% <57.69%> (-2.99%)	⬇️
nc_py_api/files_sharing.py	76.81% <76.81%> (ø)
nc_py_api/__init__.py	100.00% <100.00%> (ø)
nc_py_api/constants.py	100.00% <100.00%> (ø)
nc_py_api/nextcloud.py	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

[bigcat88]

Sharing API is in minimal stage, will return to it later, will merge this as it is.