sysutils/freebsd-rustdate: new port

freebsd-rustdate is a reimplementation of freebsd-update.sh in rust. It
can fill all the basic roles of freebsd-update for binary upgrades of
your FreeBSD system, and is much faster.

WWW: https://rustdate.over-yonder.net/

PR: 281598
Event: EuroBSDcon 2024