CstDoom3 and fhDOOM features

[Patrxgt]

It would be nice to get features exclusive for CstDoom3 and fhDOOM in the dhewm3, due to preserving those features (both projects aren't updated anymore) and giving 'em to the bigger audience (both projects are Windows and 32 bit only). Of course, everything should be optional, so no one would be forced to use those additions.

[AtifArshad1995]

Looking at CstDoom3, I will say this that I don't think that gameplay related things (such has SSG/grabber in vanilla maps or chainsaw in RoE) should be added as those are more fitting for a gameplay mod.

But I do like stuff such as the aspect corrected HUD, adjustable FOV menu option, support for any screen resolution, smoke or damage feedback effect toggles and other QoL stuff.

[Patrxgt]

Those gameplay changes could be made into unlockables, where you unlock those options after beating D3 and RoE at least once.

[DanielGibson]

for CstDoom3 aspect corrected HUD, see #641