Bug 38175: (QA follow-up) DRY out PATCH handling

Bug 38175: (QA follow-up) DRY out PATCH handling

We were repeating some code for the PATCH endpoint instead of using the
existing update handling code.  This lead to two issues:

1) We weren't catching status updates on standard updates, only the
   patch.
2) We were limiting the PATCH endpoint to just status updates when it
   could happily be used for other fields too.

This patch removes the introduction of the 'edit' method from both the
REST controller and the corresponding object and moves the logic into
the store method of the object where it's easily testable.

We also DRY out the notice sending code a little for re-use.

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>