lavapipe: NV_device_generated_commands

lavapipe: NV_device_generated_commands

this adds sufficient handling to pass the vkd3d-proton tests as well
as running cts on zink, which is gonna have to be enough since there's
no vkcts

it works by dynamically generating a vk_cmd_queue list of commands just
like the regular cmd queue would generate, with the minor change that
the final link has a nulled next pointer to correctly handle buffer copies,
where the last link would otherwise have a next pointer pointing to the
original cmd list

Acked-by: Dave Airlie <airlied@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23394>