lavapipe: Use generated code for recording of commands

I needed a deferred command queue for panvk for commands that cannot be recorded if we don't have a framebuffer yet, and saw that lavapipe already had such infrastructure for all of its commands. Other drivers might be able to use it, likely v3dv.

Most of the work would have been replacing lavapipe-isms from the structures, so I chose to generate the code that doesn't have any of that, and move the processing to the execution phase.

It's still not fully working, ran out of time before my holidays.

We could remove a further 1k lines if we generated the entry points for commands, plan to look at it when I'm back.