Bug 15803: Koha::AuthorisedValues - Remove C4::Koha::GetAuthorisedValueCategories

Bug 15803: Koha::AuthorisedValues - Remove C4::Koha::GetAuthorisedValueCategories

The subroutine C4::Koha::GetAuthorisedValueCategories just retrieves all
the authorised value categories.
We already have a method in the Koha::AuthorisedValues module to do this
job, let's use it!

Technical explanations:
The new subroutine of the AuthorisedValues TT plugin will allow to get
the authorised value categories from the templates.
The new html_helpers include file will get rid of the if selected else
end statements. Bug 15758 already uses this file, see the commit
description for more informations.

Test plan:
1/ Create or edit a new fund (aqbudgets.pl), the fields "statistic 1"
and "statistic 2" should be correctly filled with the list of authorised
value categories
2/ Edit subfields for a biblio and authority framework.
The "Authorized value" dropdown list should be correctly filled on both
pages
3/ Create new items search fields (from the administration area), same
as previously, the authorised value category dropdown list should be
correctly filled
4/ Add and edit patron attribute types, check the authorised value
category list.

Signed-off-by: Aleisha Amohia <aleishaamohia@hotmail.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>