fix the shader compile warnings ffs

[alandtse]

Good first task for someone learning hlsl want wanting to contribute.

1. Turn on debug message logging.
2. Compile all hlsl shaders (easiest it to enable diskcache and restart).
3. Marvel at how many stupid warnings we have that are probably harmless until it actually isn't.

[2024-09-16 01:44:05.056] [debug] [8800] [ShaderCache.cpp:1410] Shader logs:
WaterLighting/WaterCaustics.hlsli(46,11-75): warning X3206: implicit truncation of vector type
Common/PBR.hlsli(328,3-80): warning X3206: implicit truncation of vector type
Common/PBR.hlsli(335,3-83): warning X3206: implicit truncation of vector type
Common/PBR.hlsli(343,3-62): warning X3206: implicit truncation of vector type
Skylighting/Skylighting.hlsli(80,31-49): warning X3203: signed/unsigned mismatch, unsigned assumed
Common/ShadowSampling.hlsli(48,19-33): warning X3203: signed/unsigned mismatch, unsigned assumed
Common/ShadowSampling.hlsli(61,97-127): warning X3206: 'dot': implicit truncation of vector type
Common/ShadowSampling.hlsli(87,28-52): warning X3203: signed/unsigned mismatch, unsigned assumed
Common/ShadowSampling.hlsli(118,9-153): warning X3206: implicit truncation of vector type
Common/ShadowSampling.hlsli(123,10-167): warning X3206: implicit truncation of vector type
Common/ShadowSampling.hlsli(139,57-103): warning X3206: implicit truncation of vector type
Common/ShadowSampling.hlsli(146,2-84): warning X3206: implicit truncation of vector type
Common/ShadowSampling.hlsli(161,8-77): warning X3206: implicit truncation of vector type
Common/ShadowSampling.hlsli(222,8-88): warning X3206: implicit truncation of vector type
Common/ShadowSampling.hlsli(224,9-92): warning X3206: implicit truncation of vector type
Common/ShadowSampling.hlsli(241,8-88): warning X3206: implicit truncation of vector type
Common/ShadowSampling.hlsli(246,9-84): warning X3206: implicit truncation of vector type
E:\SteamLibrary\steamapps\common\SkyrimVR\Data\Shaders\Lighting.hlsl(1632,9-38): warning X3206: implicit truncation of vector type
E:\SteamLibrary\steamapps\common\SkyrimVR\Data\Shaders\Lighting.hlsl(1796,19-142): warning X3206: 'WetnessEffects::GetRainDrops': implicit truncation of vector type
E:\SteamLibrary\steamapps\common\SkyrimVR\Data\Shaders\Lighting.hlsl(1918,22-124): warning X32

4. Fix the warnings. Some are stupid obvious like "implicit truncation". Feel free to skip if you're not comfortable.

[Pentalimbed]

Oh no you included the ffs part too 😂?