Unbreak openzfs ports

Revamp the Makefiles for openzfs and openzfs-kmod:

• Bump port versions
• Update to a more recent commit
• Regen distinfo
• Add TESTS option to make ZTS installation optional
• Add descriptions for options
• Add missing run-time dependency on py-sysctl with PYTHON option
• Regen pkg-plist for openzfs
• Generate metadata headers post-patch
• Fix some inconsistent whitespace
• Remove unnecessary PLIST_SUB manipulation (automated by OPTIONS_SUB=yes)
• Unbreak openzfs-kmod

Approved by: wg (ports)
Approved by: mav (mentor)
Sponsored by: iXsystems, Inc.
Differential Revision: https://reviews.freebsd.org/D23854