api: quarantine: decode addresses before delivery/userlisting

api: quarantine: decode addresses before delivery/userlisting

With the change of using reinject_local_mail for the quarantine
delivery the issue of not properly decoding the entries we get from
the database before delivering became apparent

The database returns utf-8 encoded strings, reinject_local_mail and
add_to_blackwhite expects perl-strings (with wide characters) and
encodes them (a second time) - this patch decodes the database strings
before passing it on.

add_to_black_white is used in a few API calls (via
read_or_modify_user_bw_list), therefore the approach of decode (from
database), and encode (for database) was chosen.

Reported-by: Dominik Csapak <d.csapak@proxomox.com>
Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
Reviewed-by: Dominik Csapak <d.csapak@proxmox.com>
Tested-by:  Dominik Csapak <d.csapak@proxmox.com>