Bug 31385: Allow searching a CMS page by code

Bug 31385: Allow searching a CMS page by code

Test plan:
Add a CMS page with two languages for it.
Look at the code column in the DB.
Try opac/opac-page.pl?code=[CODE]&lang=[LANG]. Test leaving lang
empty and passing various languages.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Edit: I squashed the lang => language patch