C_GLClear::E_ClearBits move to Renderer

[RohacekD]

Is your feature request related to a problem? Please describe.
Clear colour bits should be generalized in the Renderer module. It is not specific for the OpenGL implementation of render.

Describe the solution you'd like
One possible destination for this enum is Renderer\Definitions.h.

Additional context
I need this kind of small changes in order to be better prepared for Vulkan renderer implementation.