WIP: enh: use @nextcloud/y-http provider

[max-nextcloud]

This is still work in progress. Just created the PR to track TODOs and so on.

Fixes #7283.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 99.48187% with 1 line in your changes missing coverage. Please review.

Project coverage is 59.05%. Comparing base (72e3453) to head (97d23a2). Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/components/Editor/GuestNameDialog.vue	0.00%	1 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7311      +/-   ##
==========================================
+ Coverage   52.18%   59.05%   +6.86%     
==========================================
  Files         483      484       +1     
  Lines       41918    37095    -4823     
  Branches     1047     1047              
==========================================
+ Hits        21875    21905      +30     
+ Misses      19940    15087    -4853     
  Partials      103      103              

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[max-nextcloud]

A lot of prep work landed in main since and there's no point in rebasing this PR. Better rebuild the commits on top of what we have now.