vulkan/wsi/wayland: drop wl_drm, generalize modifier handling
Nowadays, all Wayland compositors implement linux-dmabuf. We shouldn't need to support the legacy wl_drm interface anymore.
Instead of having hard-coded lists of modifiers for argb8888 and xrgb8888, store a list of modifiers alongside each VkFormat. To achieve this goal, introduce a new struct wsi_wl_format that holds both a VkFormat and a modifier list, and use it for the items in the formats list.
This commit unlocks non-{A,X}RGB8888 formats, which were previously always disabled for linux-dmabuf.
Depends on !11589 (merged)