0032083: Visualization, TKOpenGl - PBR rendering is unavailable on Apple A12 Bionic...

0032083: Visualization, TKOpenGl - PBR rendering is unavailable on Apple A12 Bionic (iPad)

Added "#define occLight_Index(theId) 0" workaround allowing to compile
a single light source PBR shading program on OpenGL ES 2.0,
as it disallows non-constant index expressions (even trivially deducable at compile-time).

PBR lookup table is now automatically resized to RGBA format
when RG texture format is unsupported (OpenGL ES 2.0).

OpenGl_ShaderManager now allows compiling PBR shaders
using WebGL 1.0 + GL_EXT_shader_texture_lod extension.

PBR IBL baking GLSL program has been redisigned to use
if/else to avoid non-constant index expressions.
Diffuse baking implements packing float values into a temporary RGBA8 texture
as a fallback solution on WebGL 1.0 implementations supporting float textures
but not as FBO render targets.

OpenGl_PBREnvironment now uses GL_FRAMEBUFFER instead of GL_DRAW_FRAMEBUFFER
for compatibility with OpenGL ES 2.0.