BlockModelRenderer.BrightnessCache has poor mappings

[Technici4n]

The general idea should be as follows. I let you figure out the exact name.
getInt -> getLightmap
getFloat -> getAo

[PepperCode1]

The renames for the brightness cache are not so straightforward. All uses of light and AO should also be reconsidered and made consistent with whatever the new standard terms are. These uses include the Block and BlockState methods that return the AO values, at least. Indigo and Sodium should also adapt to the new names.

lightmap to describe "packed light texture/light map coordinates" is okay and it is what I am used to, but lightmap really describes the texture itself more than coordinates for it. light, packedLight, lightCoords, or lightUv may be better names.

ao to describe the ambient occlusion value is not enough, I think. Such a name might give a wrong impression of how the value works. 1 is no AO, while 0 is all AO. aoMultiplier or aoBrightness may be a better name.