New port: emulators/emulationstation

EmulationStation is a cross-platform graphical front-end for
emulators, with controller navigation.

Originally written by Alec "Aloshi" Lofquist, this is a fork by
RetroPie.

WWW: https://github.com/RetroPie/EmulationStation

PR: 230537
Submitted by: freebsd@coombscloud.com