[Title] Use extensions GL_EXT_texture_format_BGRA8888 and GL_EXT_unpack_subimage...

[Title] Use extensions GL_EXT_texture_format_BGRA8888 and GL_EXT_unpack_subimage in TextureMapperGL.
[Issue#] TIVI-641
[Problem] GenX drivers dont support Lock Surface.
[Solution] GenX drivers dont support EGLLockSurface extension and thus Locked surface and shared surface usage had to be disabled
           for IVI. In this sceanrio where we would end up using BitmapTextureGL, it would be efficient to take into use
           GL_EXT_texture_format_BGRA8888 and GL_EXT_unpack_subimage when available. This patch adds support for taking this
           extensions into use as needed.