dns/powerdns: fix pkg-plist, pidfile in rc.d script and more

• Add missing entries to pkg-plist
• Add ixfrdist tool
• Change pidfile back to ${name}.pid in the rc.d script
• Pet portlint a bit (regenerate files/patch-configure and ran Makefile though portfmt)
• Remove patch-dns_random.cc (only needed on 12.0, which is EoL)
• Move upgrade instructions from pkg-install to pkg-message
• Bump PORTREVISION
• Upgrading the port now shows a message about required schema changes for several backends.

PR: 246434
Submitted by: Ralf van der Enden <tremere@cainites.net> (maintainer)
Reported by: Dominik Lisiak <dominik.lisiak@bemsoft.pl>