Bug 26063: Use Koha::Plugins->call for circulation hooks

Bug 26063: Use Koha::Plugins->call for circulation hooks

This patch gets rid of a helper method used for calling the plugin
hooks.

To test:
1. Run:
   $ kshell
  k$ prove t/db_dependent/Koha/Plugins/Circulation_hooks.t
=> SUCCESS: Tests pass!
2. Apply this patch
3. Repeat 1
=> SUCCESS: Tests still pass!
4. Sign off :-D

Sponsored-by: ByWater Solutions
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>