Bug 7380: Refactor the patron search box header

Bug 7380: Refactor the patron search box header

A lot of page uses the patron search box header include (git grep
patron-search.inc for the list) and the branch and category lists are
not generated for all of them.

For instance, on a patron detail page, there is a [+] link, but nothing
append on clicking on it.

This patch add a new template plugin "Categories" to get all patron
categories from the templates.

Test plan:
1/ Verify the [+] is working on all patron page (if that works for 2,
that should work for all).
2/ Launch a search from the header box and verify the library and
category dropdown lists select the correct value.
3/ Launch a search on the patron search page (patron home) and verify
the search is working correctly on selecting a category and/or a library

Followed test plan. Works as expected.
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Nicole Engard <nengard@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>