These days, we can query it with gsk_vulkan_render_get_context().
Makes quite a few functions require one less argument.
And it also makes the GskVulkanRenderPass empty. Gotta figure out what
to do with it.
This is a massive refactoring because it collects all the renderops
of all renderpasses into one long array in the Render object.
Lots of code in there is still flaky and needs cleanup. That will
follow in further commits.
Other than that it does work fine though.
Instead of creating the op manually, just pass in the renderpass and
have the op created from there.
This way ops aren't really initialized anymore, they are more appended
to the queue, so instead of foo_op_init() we can just call the function
foo_op().
