Don't use GL Matrix Stack on OpenGL 2 backend

Currently the GL Matrix Stack is also used with OpenGL 2.
That is pushMatrix, multMatrix and popMatrix are executed
although this does not influence the rendering at all. The
OpenGL 1 matrices are not passed to the shaders.

With this change the calls to the matrix stack are no longer
executed if the Shader based backend is used. This means we
have a few less matrix multiplications in the rendering.

Mostly affects a few effects which have not yet completely be
ported over to OpenGL 2.

BUG: 303093
FIXED-IN: 4.10
REVIEW: 105455