Bug 36758: Add TICKET_ASSIGNED notice

Bug 36758: Add TICKET_ASSIGNED notice

This patch adds a new default TICKET_ASSIGNED notice to be used with
catalog concerns to notice the assigned staff user when a ticket has
been assigned to them.

Test plan
1) Run the database update and confirm that the new notice has been
   added to the database (If on the sandboxes, skip to the next patch)

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>