Sort relationship types/attributes pages (MBS-1955)
MBS-5873: Correctly link label conflicts to label pages

My fix for MBS-5696 made ModBot leave comments when an edit would
cause a violation of duplicate rows, but I incorrectly hard-coded
the URL path for artists, even if the error was thrown for labels.
This commit moves the URL generation to subclasses, and changes
the wording to mention the more general 'entity', rather than
artist or label.
Adding lyricsnmusic to the whitelist
Added test
Use twice as much code for sorting
Use sorted_children instead of sorted_attributes
Fix Data::Editor tests to account for collection subscriptions
Merge branch 'mbs-5873' into beta

* mbs-5873:
  MBS-5873: Correctly link label conflicts to label pages
Merge remote-tracking branch 'nikki/sortrelationships' into beta

* nikki/sortrelationships:
  Use sorted_children instead of sorted_attributes
  Use twice as much code for sorting
  Sort relationship types/attributes pages (MBS-1955)
Merge remote-tracking branch 'reosarevok/mbs-5849' into beta

* reosarevok/mbs-5849:
  Added test
  Adding lyricsnmusic to the whitelist

Conflicts:
	root/static/scripts/tests/Control/URLCleanup.js