Move shaders into glsl and hlsl directories

Move `data/shaders` to `data/shaders/glsl`
Move `data/hlsl` to `data/shaders/hlsl`

Fix up shader paths in the cpp files to point to the new glsl location.

`data/shaders/hlsl/compile.py` still overwrites the glsl .spv files (for
now).

Issue: #723

data/shaders/pushconstants/lights.frag

@@ -1,37 +0,0 @@
-#version 450
-
-#define lightCount 6
-
-layout (location = 0) in vec3 inNormal;
-layout (location = 2) in vec3 inColor;
-
-layout (location = 3) in vec4 inLightVec[lightCount];
-
-layout (location = 0) out vec4 outFragColor;
-
-#define MAX_LIGHT_DIST 9.0 * 9.0
-
-void main() 
-{
-	vec3 lightColor[lightCount];
-	lightColor[0] = vec3(1.0, 0.0, 0.0);
-	lightColor[1] = vec3(0.0, 1.0, 0.0);
-	lightColor[2] = vec3(0.0, 0.0, 1.0);
-	lightColor[3] = vec3(1.0, 0.0, 1.0);
-	lightColor[4] = vec3(0.0, 1.0, 1.0);
-	lightColor[5] = vec3(1.0, 1.0, 0.0);
-	
-	vec3 diffuse = vec3(0.0);
-	// Just some very basic attenuation
-	for (int i = 0; i < lightCount; ++i)
-	{				
-		float lRadius =  MAX_LIGHT_DIST * inLightVec[i].w;
-	
-		float dist = min(dot(inLightVec[i], inLightVec[i]), lRadius) / lRadius;
-		float distFactor = 1.0 - dist;		
-	
-		diffuse += lightColor[i] * distFactor;		
-	}
-			
-	outFragColor.rgb = diffuse;			
-}