zink: fix general layout on radv

When using a resource in the GENERAL-layout, we need to always insert barriers, and we need to mark those barriers as read-write. The reason for this is that this layout is used for blits within the same resource, which is the only layout that is allowed for this.

We also need to avoid transitioning textures to the GENERAL-layout like we currently do, to avoid terrible performance. I'll write up some patches for that as well soon, but it turns out it's a bit more tricky than it sounds at first. I just want to post this as-is for visibility.

Closes: #3790 (closed)