TPAC Org unit hiding

TPAC Org unit hiding

Adds support for the opac.org_unit_hiding.depth org unit setting to
TPAC, which makes out-of-scope org units disappear (except when
explicitly requested).

Ui changes:

All search org unit selectors
Holds pickup lib selector
Copy summary in search results page
Copy list in search results page
Copy summary in record detail page (which controls the copy grid).

Org unit hiding is based on the physical_loc (Physical Location) param /
cookie, which is the closest analog to 'ol' (original location), from
which it was based in the JSPAC.

Signed-off-by: Bill Erickson <berick@esilibrary.com>