Renderer: add antialiasing options to hardware renderer

[SirYodaJedi]

As something to consider down the road when the code is closer to the landmark release, I think the engine should have some sort of configurable antialiasing. As mentioned in a similar discussion for jkgfxmod (jdmclark/jkgfxmod#25), proper Halton-sampled FSAA would be ideal, as the low-detail, nearest-neighbor-filtered textures make texture aliasing particularly noticeable. I find aliasing more distracting at SD and HD resolutions compared to LD resolutions like 320x200 or 240p, so this would be a much-appreciated QoL enhancement.

[luciusDXL]

Antialiasing options are definitely planned for the future.

[Q3BFG10K]

Seconded. While nVidia's FXAA does a good job, having in-game MSAA or high quality FXAA/SMAA would be more convenient.

Hopefully we'll also get trilinear filtering.