Enable processor to actually look for existing lexicon strings by not setting the _trans fields in modcontextsetting.class.php
also do it for sqlsrv
replaced context setting getlist processor with a class based one (dupe of system settings processor with a few changes)
Revert modcontextsetting.class.php changes, now this PR consists only of a new class based processor
Merge remote-tracking branch 'upstream/pr/11947' into pr/11947

* upstream/pr/11947:
  Revert modcontextsetting.class.php changes, now this PR consists only of a new class based processor
  replaced context setting getlist processor with a class based one (dupe of system settings processor with a few changes)
  also do it for sqlsrv
  Enable processor to actually look for existing lexicon strings by not setting the _trans fields in modcontextsetting.class.php