Missed these OpenGL2 variants with the mass rename

Change-Id: I8a4613135ec43e0b1c161c99a3c393a07d68aed3
Brought more of the OpenGL module logic over

Made the vtkGUISupportQt module work, moved the other QtOpenGL module
to OpenGL backend only for now - uses vtkgl/extension manager stuff.
Configure the header with options selected for the build.

Change-Id: I7099e6c110ba080bb102e180d6d544ad3515c730
OpenGL and OpenGL2 are mutually exclusive

There may be a better way to do this with module logic, but for now
ensure we don't try to build both.

Change-Id: I2f163d0f52380ea7a1ef552b2bb027695d54bf6d