Support GLES in internal shaders

[Shivansps]

1. Added conditional presicion quantifiers
2. Implement software varying cull distance for GLES (the instruction to support hardware cull is very rare)
3. For ES default-material glsl files were manually generated and copied directly
4. Removed usage glBindFragDataLocation() for both GL and GLES now all fragOutN use location=N in shader.

Notes:
-there is a few prs modifiying shaders to keep in mind, its likely more changes are needed after those are merged
-There is a conflict in "envmap-sphere-warp-f.sdr"

layout(location=0) out vec4 fragOut0;

layout (location = 0) out vec4 outColor;

I added location 0 to fragOut0 as that is what glBindFragDataLocation() would have given it anyway, but its in conflict with outColor... I dont see being used.

-I noticed this on main-v.sdr L193

vec4 shadowPos = shadow_mv_matrix * modelMatrix * orient * vertPosition;
vertOut.shadowPos = shadow_mv_matrix * modelMatrix * orient * vertPosition;
vertOut.shadowUV[0] = transformToShadowMap(shadow_proj_matrix[0], 0, shadowPos);
vertOut.shadowUV[1] = transformToShadowMap(shadow_proj_matrix[1], 1, shadowPos);
vertOut.shadowUV[2] = transformToShadowMap(shadow_proj_matrix[2], 2, shadowPos);
vertOut.shadowUV[3] = transformToShadowMap(shadow_proj_matrix[3], 3, shadowPos);

shadow_mv_matrix * modelMatrix * orient * vertPosition; is done twice here?

Testing:
-Tested in icarus OpenGL with all detail with both shadown on/off and NoAA, FXAA, SMAA and MSAA no issues were noticed.
-Tested Icarus on GLES on my mali phone, all is good.

[qazwsxal]

re: envmap I don't think outColor is actually used, so try deleting that line