Bug 25534: Add ability to send an email specifying a reason when canceling a hold

Bug 25534: Add ability to send an email specifying a reason when canceling a hold

Some libraries would like to be able to cancel a hold with the option to
specify a reason. Providing a reason would generate an email to that
patron.

Test Plan:
1) Apply this patch
2) Run updatedatabase.pl
3) Restart all the things!
4) Create new AV category "HOLD_CANCELLATION", add some cancelation reasons
5) Add new Holds module notice "HOLD_CANCELLATION", add an email version.
   A quick test version would be "Reason: <<reserves.cancellation_reason>>"
--
[% USE AuthorisedValues %]
Reason: [% AuthorisedValues.GetByCode( 'CANCELLATION_REASON', hold.cancellation_reason, 'IS_OPAC' ) %]

[% IF hold.cancellation_reason == "MY_AV_VALUE" %]
IF perhaps you'd like to have a much longer explanation than just the
one sentence in the AV description, you can use IF blocks using Template
Toolkit markup!
[% END %]
--
6) Place a hold for a patron
7) On request.pl, select the 'del' option for the hold
8) Select a cancellation reason and choose "Update hold(s)"
9) Note a new message has been queue for the patron with the cancelation reason
11) Test again from circulation.pl
12) Test again from moremember.pl
10) Cancel a hold with no reason, note no email is generated
11) Delete your authorised values, not the feature is disabled
12) Reinstate the authorised values, but delete the notice,
    you should now be able to cancel a hold with a reason,
    but no email will be generated

Signed-off-by: Andrew Fuerste-Henry <andrew@bywatersolutions.com>
Signed-off-by: Rebecca Coert <rcoert@arlingtonva.us>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>