Enforce "-F" flag on resuming recv of full/newfs on existing dataset

When receiving full/newfs on existing dataset, then it should be done
with "-F" flag. Its enforced for initial receive in checks done in
zfs_receive_one function of libzfs. Similarly, on resuming full/newfs
recv on existing dataset, it should be done with "-F" flag.

When dataset doesn't exist, then full/new recv is done on newly created
dataset and it's marked INCONSISTENT. But when receiving on existing
dataset, recv is first done on %recv and its marked INCONSISTENT.
Existing dataset is not marked INCONSISTENT. Resume of full/newfs
receive with dataset not INCONSISTENT indicates that its resuming newfs
on existing dataset. So, enforce "-F" flag in this case.

Also return an error from dmu_recv_resume_begin_check() in zfs kernel,
when its resuming full/newfs recv without force.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Chunwei Chen <david.chen@nutanix.com>
Signed-off-by: Jitendra Patidar <jitendra.patidar@nutanix.com>
Closes #13856
Closes #13857

contrib/pyzfs/libzfs_core/_constants.py

@@ -101,6 +101,7 @@ zfs_errno = enum_with_offset(1024, [
         'ZFS_ERR_BADPROP',
         'ZFS_ERR_VDEV_NOTSUP',
         'ZFS_ERR_NOT_USER_NAMESPACE',
+        'ZFS_ERR_RESUME_EXISTS',
     ],
     {}
 )