aux/cso: try harder to keep cso state in sync on cso context unbind

Before a73cb106, cso contexts were never reused, but now that they are we need to be extra careful that the state in the cso context and in the pipe context matches even after an unbind, since when the cso context is reused the state might otherwise get out of sync (as there is no concept of "initial state", basically cso always relied on the default values being the same both in cso and the drivers). This fixes some errors we've seen internally with lavapipe.

Fixes: a73cb106