ZFS: fix the delegate tests
These tests have never worked correctly
- Replace runwattr with sudo
- Fix a scoping bug with the "dtst" variable
- Cleanup user properties created during tests
- Eliminate the checks for refreservation and send support. They will always be supported.
- Fix verify_fs_snapshot. It seemed to assume that permissions would not yet be delegated, but that's not how it's actually used.
- Combine verify_fs_promote with verify_vol_promote
- Remove some useless sleeps
- Fix backwards condition in verify_vol_volsize
- Remove some redundant cleanup steps in the tests. cleanup.ksh will handle everything.
- Disable some parts of the tests that FreeBSD doesn't support:
- Creating snapshots with mkdir
The sharenfs parts could probably be reenabled with more work to remove the
MFC after: 2 weeks
Sponsored by: Axcient
Differential Revision: https://reviews.freebsd.org/D21898