Bug 18399: Add reasons in edit suggestion page

Bug 18399: Add reasons in edit suggestion page

Test plan:

 - Fill the authorised values's category 'SUGGEST' with reason
 - Edit a pending suggestion. Set the status to rejected
   and select a reason
 - Check the reason has been saved (i.e in the suggestions
   table of rejected tab)
 - Check in the corresponding message_queue that the reason
   is here
 - Re-edit the same suggestion
 - Check that the correct reason is selected by defaut
 - Edit an other pending suggetion. Set the status to rejected,
   select other reason and fill the input text
 - Re-edit the previews suggestion and make sure the input
   "other" is displayed by default with the correct value

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>