Bug 36490: Correct tab-switching keyboard shortcut for header search forms

Bug 36490: Correct tab-switching keyboard shortcut for header search forms

This patch updates staff-global.js so that we correctly define the
keyboard shortcuts for search header tabs following the switch to using
the WRAPPER for tabs in Bug 35850.

To test, apply the patch clear your browser cache if necessary.

- Go to the staff interface.
- Test each keyboard shortcut to confirm that the header search tabs
  activate correctly:
  - Check in: Alt-r
  - Renew: Alt-w
  - Search: Alt-q
  - Check out: Alt-u
- Test that the keyboard shortcut takes you to the correct page if the
  header search form doesn't exist on the page, e.g. the Authorities
  home page.

Signed-off-by: Andrew Fuerste Henry <andrewfh@dubcolib.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>