Fix autoload constant lookup dependency issue

Also patch existing classes

ee/app/services/groups/autocomplete_service.rb

 module Groups
-  class AutocompleteService < BaseService
+  class AutocompleteService < Groups::BaseService
     def labels(target = nil)
       labels = LabelsFinder.new(
         current_user,

ee/app/services/groups/participants_service.rb

 module Groups
-  class ParticipantsService < BaseService
+  class ParticipantsService < Groups::BaseService
     include Users::ParticipableService
 
     def execute(noteable)