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/glsl/viewportarray/scene.vert

@@ -0,0 +1,15 @@
+#version 450
+
+layout (location = 0) in vec3 inPos;
+layout (location = 1) in vec3 inNormal;
+layout (location = 2) in vec3 inColor;
+
+layout (location = 0) out vec3 outNormal;
+layout (location = 1) out vec3 outColor;
+
+void main() 
+{
+	outColor = inColor;
+	outNormal = inNormal;
+	gl_Position = vec4(inPos.xyz, 1.0);	
+}