Bug 21547: Use set_password in opac-passwd and remove sub goodkey

Bug 21547: Use set_password in opac-passwd and remove sub goodkey

Remove sql statement to change password by calling set_password.
Remove sub goodkey by calling C4::Auth::checkpw_hash.
Adding the scalar before param Oldkey (from bug 21036).

Rebased on top of 21178 (using set_password instead of update_password).

Test plan:
Try to change password in OPAC with good and bad pw.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>