Only report remote id once per job

Created MR!2 for the issue mentioned, please review.
Thank you.

Thank you for giving this a try, i checked the original code:

The addRemoteMapping can not change, since we then would break identifying the item when translations return.

The addMessage should move to the job outside of the loop.

Supertext identifies item ids by just receiving GroupId (translation job item ids) and we don't need (and we don't get) a per-item remote id.

@miro_dietiker I had made changes to the MR!2, please review.
Thank You.

no need to add to the job item. no need to collect and group the ids, because it's always the same.