Do not persist user/group/project quota zap objects when unneeded

In the zfs_id_over*quota functions, there is a short-circuit to skip
the zap_lookup when the quota zap does not exist. If quotas are never
used in a zpool, then the quota zap will never exist. But if
user/group/project quotas are ever used, the zap objects will be
created and will persist even if the quotas are deleted.

The quota zap_lookup in the write path can become a bottleneck for
write-heavy small I/O workloads. Before this commit, it was not
possible to remove this lookup without creating a new zpool.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Sam Atkinson <samatk@amazon.com>
Closes #14721