Bug 15407: Koha::Patron::Categories - replace C4::Category->all

Bug 15407: Koha::Patron::Categories - replace C4::Category->all

The C4::Category module contained only 1 method to return the patron
categories available for the logged in user.
The new method Koha::Patron::Categories->search_limited does exactly the
same thing (see tests) and must be used in place of it.

Test plan:
- Same prerequisite as before
For the following pages, you should not see patron categories limited to
other libraries.
- On the 'Item circulation alerts' admin page
  (admin/item_circulation_alerts.pl), modify the settings for check-in
  and checkout (NOTE: Should not we display all patron categories on
  this page? If yes, it must be done in another bug report to ease
  backporting it).
- Search for patrons in the admin (budget) and acquisition (order) module.
- On the patron home page (search form in the header)

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>