Bug 36652: Pass copy_form template variable

Bug 36652: Pass copy_form template variable

To test:

1. Go to Tools > Notices and slips
2. Pick any notice and try to copy it to another library using the 'Copy notice' column.
3. You are redirected to a blank screen and if you go back to the Notices and slips page the notice has not been copied.
4. APPLY PATCH
5. Try steps 1 - 3 again, but this time you should be correctly directed.

Signed-off-by: Roman Dolny <roman.dolny@jezuici.pl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
(cherry picked from commit 0e7d2c3db4727c629ab76e01a3f42d6810c89916)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>