Taking account of the new zone append write operation for zoned devices,
BLOCK_ACCT_ZONE_APPEND enum is introduced as other I/O request type (read,
write, flush).

Signed-off-by: Sam Li <faithilikerun@gmail.com>
Message-id: 20230508051916.178322-3-faithilikerun@gmail.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>