LP#1477154-Placing holds fails unintuitively when preferred pickup location is disabl...

LP#1477154-Placing holds fails unintuitively when preferred pickup location is disabled via org unit setting opac.holds.org_unit_not_pickup_lib

Added a check in javascript that should fire when loading the page. Adds a
warning in red text, turns the org_selector yellow (like when the date
is invalid) and disables the submit button. These are all undone when
they select a different option, and never happen if their settings don't
prefer an invalid org.

Changed to a different shade of yellow and red that seemed better for
accessibility.

Steps to test:
[1] Go to Administration -> Local Administration -> Library Settings
Editor
[2] Make sure opac.hold.org_unit_not_pickup_lib is set to true for some
library
[3] Find a patron whose home library is set to that library and one
whose home library isn't
[4] Log in to the first patron and attempt to place a hold
[5] Observe the holds page
[6] Change the pickup library of the hold
[7] Observe the holds page
[8] Log in to the second patron and attempt to place a hold
[9] Observe

Never did find out when these bad hold requests bounced and why they
redirected to the same page.

Signed-off-by: Steven Mayo <smayo@georgialibraries.org>
Signed-off-by: Andrea Buntz Neiman <abneiman@equinoxOLI.org>
Signed-off-by: Terran McCanna <tmccanna@georgialibraries.org>