Bug 10937: Option to hide and group itemtypes from advanced search

Bug 10937: Option to hide and group itemtypes from advanced search

This allows to group certain item types in a category, to be displayed (and searched) as such in OPAC's advanced search.  For example, you can group Reserve 2h and Reserve 12h into a Reserve category.  The 2 and 12h types won't appear anymore.
This also allows to simply prevent an item type from displaying as a search option.

TEST PLAN
------------------
0) Back up database, so you can reset and retest easily. ;)
1) Apply the patch
2) Run Koha QA tool.
3) prove -v t/db_dependent/Koha.t
  -- all tests should pass.
  4) run ./installer/data/mysql/updatedatabase.pl to add the
  two columns to itemtypes
  -- Does a meaningful message get printed?
  Are the columns added?
  "DESCRIBE itemtypes;" should list hideinopac and searchcategory.
  5) You need to add a category to group your item types:
  a) In Intranet/Koha Admin/Authorized values,
  select DOCTYPECAT in the 'Show category:' dropdown
  i) If you do not have a DOCTYPECAT category, create one.
  b) Click button "New authorized value for DOCTYPECAT"
  c) Enter
  Authorized value: HARDWARE
  Description : Hardware
  Description (OPAC): Hardware
  6) Group your items under that new category
  a) In Intranet/Koha Admin/Item types, choose (at least)
  two item types and for each:
  - Click action/Edit on the right column
  - Third row (below Description) is the Search category list box, select Hardware
  - click Save changes at the bottom
  7) Select at least one item to be hidden in the OPAC search
  a) In Intranet/Koha Admin/Item types (again), choose a different item type:
  -  Click action/Edit
  -  Click the checkbox "Hide in OPAC" below the list of icons.
  8) Go test your modifications
  a) Go to OPAC/Adv search.
  b) Validate that all items modified above (hidden or grouped) do not appear in Item type list
  c) Validate that new item type Hardware does appear instead.
  d) Select item Hardware, start Search.
  ) Validate returned items are the of the two types that were grouped into the Hardware category in step 4.

Sponsored-by: Vanier college
Signed-off-by: Nick <nick@quecheelibrary.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>