The OpenGL spec defines GL_CLAMP's formula similarly to CLAMP_TO_EDGE
and CLAMP_TO_BORDER depending on the filter mode used. It doesn't
exactly behave like this, but it's the closest we can get with what
Vulkan offers without emulating it by injecting shader code.
Abstracted ComponentType was not being used in a meaningful way.
This commit drops its usage.
There is one place where it was being used to test compatibility between
two cached surfaces, but this one is implied in the pixel format.
Removing the component type test doesn't change the behaviour.
