Add games/idtech4a-engine

[tx00100xt]

Hello! This is a port of idTech4A++ Engine, providing the game (Doom 3 /Prey / Quake 4) for OpenBSD. It is open source based on id-Software/DOOM-3: Doom 3 GPL source release and restored clients for Prey and Quake4. Uses GPL-3 licensed SDK for android versions of the game: https://github.com/glKarin/idtech4amm_doom3_sdk https://github.com/glKarin/idtech4amm_quake4_sdk https://github.com/glKarin/idtech4amm_prey_sdk since the project was originally for android.

Tested on amd64 architecture on OpenBSD 7. 7 installed on real hardware: ASUS TUF GAMING B450M-PRO II AMD Ryzen 5 5600G AMD Radeon RX 580 PowerColor. (amdgpu)

Works as good as on Linux.

send to ports@ 2025-19-05

Video: https://www.youtube.com/watch?v=KaN5iB0dEYI https://www.youtube.com/watch?v=V1f6vknHgfw https://www.youtube.com/watch?v=vLWXX1UwX9c

I want to add this to the official ports tree, so please leave any feedback or suggestions on how to improve it. Thanks!

Source on Github: https://github.com/glKarin/com.n0n3m4.diii4a