VacationDialog: Add mailaction
We need different mailActionsfor vacationdialog:
Keep, Discard, Send To, Copy To
I created the testfiles out of scripts from roundcubemail.
Tested, that the createdscript is parseable by rcm.
(cherry picked from commit 1572d9cde0c85ed7325b9a745fef0c925d044c72)