Adding a "/draft" alias to the "/wip" command

Also including a few specs

lib/gitlab/quick_actions/merge_request_actions.rb

@@ -80,7 +80,7 @@ module Gitlab
             # Allow it to mark as WIP on MR creation page _or_ through MR notes.
             (quick_action_target.new_record? || current_user.can?(:"update_#{quick_action_target.to_ability_name}", quick_action_target))
         end
-        command :wip do
+        command :wip, :draft do
           @updates[:wip_event] = quick_action_target.work_in_progress? ? 'unwip' : 'wip'
         end
 

spec/services/quick_actions/interpret_service_spec.rb

@@ -1036,6 +1036,16 @@ RSpec.describe QuickActions::InterpretService do
       let(:issuable) { merge_request }
     end
 
+    it_behaves_like 'wip command' do
+      let(:content) { '/draft' }
+      let(:issuable) { merge_request }
+    end
+
+    it_behaves_like 'unwip command' do
+      let(:content) { '/draft' }
+      let(:issuable) { merge_request }
+    end
+
     it_behaves_like 'empty command' do
       let(:content) { '/remove_due_date' }
       let(:issuable) { merge_request }