Bug 18779: Translatability: Get rid of exposed tt directives in authorities-search...

Bug 18779: Translatability: Get rid of exposed tt directives in authorities-search-results.inc (OPAC)

The file opac-tmpl/bootstrap/en/includes/authorities-search-results.inc
exposes template directives to translation where translators should not
be confronted with.

Example:
"[%% PROCESS showreference heading=seeals.heading linkType='seealso' "
"type=seeals.type authid=seeals.authid %%] "

To test:
- Apply patch
- Verify that Authority search in OPAC works as before
- Bonus test: create a new language 'aa-AA', verify that line above
  does not show up in aa-AA-opac-bootstrap.po

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>