Replace ticket id with transfer id in logs

[nirs]

Following bug https://bugzilla.redhat.com/2043283, imageio log the ticket id
for tracking requests. This is wrong since the ticket id is sensitive information
and the way we track image transfers in all other components is using the transfer
id.

Here example logs using the ticket id:

# grep e285c666-fde0-431b-a993-36315d651e42 /var/log/ovirt-imageio/daemon.log 
2022-01-21 00:53:06,898 INFO    (Thread-9) [tickets] [local] ADD ticket={'dirty': False, 'ops': ['read'], 'size': 6442450944, 'sparse': False, 'inactivity_timeout': 60, 'transfer_id': 'dd8e8c9e-4e74-4b57-b61a-759b5204672b', 'uuid': 'e285c666-fde0-431b-a993-36315d651e42', 'timeout': 300, 'url': 'nbd:unix:/run/vdsm/nbd/e285c666-fde0-431b-a993-36315d651e42.sock'}
2022-01-21 00:53:07,988 INFO    (Thread-11) [images] [::ffff:192.168.122.1] OPTIONS ticket=e285c666-fde0-431b-a993-36315d651e42
2022-01-21 00:53:07,989 INFO    (Thread-11) [extents] [::ffff:192.168.122.1] EXTENTS ticket=e285c666-fde0-431b-a993-36315d651e42 context=zero
2022-01-21 00:53:13,055 INFO    (Thread-17) [tickets] [local] REMOVE ticket=e285c666-fde0-431b-a993-36315d651e42

(Logs fixed by https://bugzilla.redhat.com/2043283 were removed)

I'm not sure if we should remove the ticket id from the ADD log, this need
more thinking. But for the rest of the logs, there is really no need to
show ticket=, and we can simplify replace it with transfer=.