ZFS: fix several of the "zpool create" tests

• Remove zpool_create_013_neg. FreeBSD doesn't have an equivalent of Solaris's metadevices. GEOM would be the equivalent, but since all geoms are the same from ZFS's perspective, this test would be redundant with zpool_create_012_neg

• Remove zpool_create_014_neg. FreeBSD does not support swapping to regular files.

• Remove zpool_create_016_pos. This test is redundant with literally every other test that creates a disk-backed pool.

• s:/etc/vfstab:/etc/fstab in zpool_create_011_neg

• Delete the VTOC-related portion of zpool_create_008_pos. FreeBSD doesn't use VTOC.

• Replace dumpadm with dumpon and swap with swapon in multiple tests.

• In zpool_create_015_neg, don't require "zpool create -n" to fail. It's reasonable for that variant to succeed, because it doesn't actually open the zvol.

• Greatly simplify zpool_create_012_neg. Make it safer, too, but not interfering with the system's regular swap devices.

• Expect zpool_create_011_neg to fail (PR 241070)

• Delete some redundant cleanup steps in various tests

• Remove some unneeeded ATF timeout specifications. The default is fine.

PR: 241070
MFC after: 2 weeks
Sponsored by: Axcient