[jak 2] ETIE (#2326)

Definitely needs a clean up pass, but I think the functionality is very
close.

There's a few "hacks" still:
- I am using the emerc logic for environment mapping, which doesn't care
about the length of the normals. I can't figure out how the normal
scaling worked in etie. I want to do a little bit more experimentation
with this before merging.
- There is some part about adgifs for TIE and ETIE that I don't
understand. The clearly correct behavior of TIE/ETIE is that the alpha
settings from the adgif shader are overwritten by the settings from the
renderer. But I can't figure out how this happens in all cases.
- Fade out is completely disabled. I think this is fine because the
performance difference isn't bad. But if you are comparing screenshots
with PCSX2, it will make things look a tiny bit different.

decompiler/level_extractor/extract_tfrag.cpp

@@ -2070,9 +2070,8 @@ void make_tfrag3_data(std::map<u32, std::vector<GroupedDraw>>& draws,
           vtx.z = vert.pre_cam_trans_pos.z();
           vtx.s = vert.stq.x();
           vtx.t = vert.stq.y();
-          vtx.q_unused = vert.stq.z();
-          // if this is true, we can remove a divide in the shader
-          ASSERT(vtx.q_unused == 1.f);
+          // because this is true, we can remove a divide in the shader
+          ASSERT(vert.stq.z() == 1.f);
           vtx.color_index = vert.rgba / 4;
           // ASSERT((vert.rgba >> 2) < 1024); spider cave has 2048?
           ASSERT((vert.rgba & 3) == 0);