FEATURE: provide more details when performing a bulk add to group

config/locales/client.en.yml

@@ -2600,6 +2600,7 @@ en:
         add_members: "Add members"
         custom: "Custom"
         bulk_complete: "The users have been added to the group."
+        bulk_complete_users_not_added: "These users were not added:"
         bulk: "Bulk Add to Group"
         bulk_paste: "Paste a list of usernames or emails, one per line:"
         bulk_select: "(select a group)"

config/locales/server.en.yml

@@ -255,6 +255,8 @@ en:
     delete_reason: "Deleted via post moderation queue"
 
   groups:
+    success:
+      bulk_add: "%{users_added} users have been added to the group."
     errors:
       can_not_modify_automatic: "You cannot modify an automatic group"
       member_already_exist: "'%{username}' is already a member of this group."