[stable31] fix(files): Remove obsolete loading code from old API, add public shared id to enabled view

[backportbot]

Backport of #7157

Warning, This backport's changes differ from the original and might be incomplete ⚠️

Todo

• Review and resolve any conflicts
• Amend HEAD commit to remove the line stating to skip CI

---

Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 58.57%. Comparing base (cb0fcd6) to head (a467d56).
Report is 4 commits behind head on stable31.

Additional details and impacted files

@@ Coverage Diff @@## stable31 #7181 +/- ##
============================================
+ Coverage 51.87% 58.57% +6.69% 
============================================
Files 287 286 -1 Lines 40922 36024 -4898 Branches 794 794 ============================================
- Hits 21229 21100 -129 + Misses 19572 14803 -4769 
Partials 121 121 

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