Bug 29543: Prevent user to checkin or renew items they don't own

Bug 29543: Prevent user to checkin or renew items they don't own

Checkin or renew must be restricted to the items they own.

Test plan:
Create an item with barcode bc_1
Check it in to user A
Login to SCO with user B
Get the token using the browser dev tool, from the cookie
Hit (replace $JWT)
    /cgi-bin/koha/sco/sco-main.pl?jwt=$JWT&op=renew&barcode=bc_1
    /cgi-bin/koha/sco/sco-main.pl?jwt=$JWT&op=returnbook&barcode=bc_1

You should see an error message

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>