New port: games/OpenTomb

OpenTomb is an open-source engine reimplementation project intended to
play levels from all classic-era Tomb Raider games (TR 1-5) and custom
TRLE levels. The project does not use any old Tomb Raider source
code, because all attempts to retrieve sources from Eidos / Core were
in vain.

WWW: https://opentomb.github.io/

PR: 218883
Submitted by: Piotr Kubaj <pkubaj@anongoth.pl>
Approved by: lme (mentor)
Differential Revision: https://reviews.freebsd.org/D10664