Migrate groups fetch to ocs api

[skjnldsv]

Use our ocs api instead of old group controller legacy in settings

I reformatted the files:
the only real change is:
https://github.com/nextcloud/server/pull/9296/files?w=1

$.ajax({url: OC.linkToOCS('cloud/groups',2)+'details',dataType: 'json',success: function(data){varresults=[];if(data.ocs.data.groups&&data.ocs.data.groups.length>0){data.ocs.data.groups.forEach(function(group){if(!options.excludeAdmins||group.id!=='admin'){results.push({id: group.id,displayname: group.displayname});}})

[codecov]

Codecov Report

Merging #9296 into master will increase coverage by <.01%.
The diff coverage is n/a.

@@ Coverage Diff @@## master #9296 +/- ##
============================================
+ Coverage 51.93% 51.93% +<.01% 
Complexity 25389 25389 ============================================
Files 1608 1608 Lines 95436 95436 Branches 1394 1394 ============================================
+ Hits 49563 49564 +1 + Misses 45873 45872 -1

Impacted Files	Coverage Δ	Complexity Δ
lib/private/Files/Cache/Propagator.php	96.2% <0%> (+1.26%)	16% <0%> (ø)	⬇️

[MorrisJobke]

Tested and works 👍

[rullzer]

Does this mean the old endpoint can die?

[nickvergessen]

It does with #8824