This tests shader uniform groups and collisions between
shaders. We build two shader IDs from the same source code,
and then subgroup three times for both shaders with different uniforms.

We draw to small blocks that have the variants attached to
eachother. One row channels will be enabled (one per block(
and for the other they will be disabled.

If two or more blocks look the same, we have some collision in
uniform group handling.
