Bug 17830: CSRF - Handle unicode characters in userid

Bug 17830: CSRF - Handle unicode characters in userid

If the userid of the logged in user contains unicode characters, the token
will not be generated correctly and Koha will crash with:
  Wide character in subroutine entry at /usr/share/perl5/Digest/HMAC.pm line 63.

Test plan:
- Edit a superlibrarian user and set his/her userid to '❤' or any other strings
with unicode characters.
- Login using this patron
- Search for patrons and click on a result.

=> Without this patch, you will get a software error (with "Wide
character in subroutine entry" in the logs).
=> With this patch, everything will go fine

You can also test the other files modified by this patch.

Signed-off-by: Karam Qubsi <karamqubsi@gmail.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>