fix(dav): remove sharing attributes from default dav fetch and change duplicate registration from error to warn

[skjnldsv]

We moved those attributes to the files_sharing app, since we can disable the app.

Fix nextcloud/server#43953

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 77.50%. Comparing base (e428bb6) to head (af001fc).
Report is 244 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #902      +/-   ##
==========================================
+ Coverage   77.17%   77.50%   +0.32%     
==========================================
  Files          17       17              
  Lines         403      440      +37     
  Branches      108      118      +10     
==========================================
+ Hits          311      341      +30     
- Misses         91       98       +7     
  Partials        1        1              

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