MBS-6325: Perform 'set_release_group_first_release_date' on release moves

When a release's release_group attribute changes, we perform
set_release_group_first_release_date to update the first release date of both
the new release group and the old release group.

Also includes a fix up script to set fix all current anomalies.
Merge branch 'mbs-6325' into beta

* mbs-6325:
  MBS-6325: Perform 'set_release_group_first_release_date' on release moves