Turns out that ElementAt for Queue<T> runs the default implementation as it doesn't implement IList, which enumerates elements of the queue up to the given index. This code was creating `count` enumerators and iterating way more queue items than it needed to at higher counts. The solution is just to use one enumerator and break out of the loop when we get the count that we need.

3.5% of backend time was being spent _just_ enumerating at the usual spot in SMO.

Mod manager

Cheat refactor

Refreshinterval

Helper shaders and post processing effects typically need some parameters to tell them what to do, which we pass via constant buffers that are created and destroyed each time.

This can vary in cost between different Vulkan drivers. It shows up on profiles on mesa and MoltenVK, so it's worth avoiding. Some games only do it once (BlitColor for present), others multiple times. It's also done for post processing filters and FSR upscaling, which creates two buffers.

For mirrors, I added the ability to reserve a range on the staging buffer for use as any type of binding. This PR allows these constant buffers to be instead temporarily allocated on the staging buffer, skipping allocation and buffer management costs entirely.

Two temporary allocations do remain:
- DrawTexture, because it doesn't have access to the command buffer scope
- Index buffer indirect conversion, because one of them is a storage buffer and thus is a little more complicated.

There's a small cost in that the uniform buffer takes up more space due to alignment requirements. At worst that's 256 bytes (on a GTX 1070) but more modern GPUs should have a better time.

Worth testing across different games and post effects to make sure they still work.

Vulkan: Enumerate Query Pool properly

Perf/push descriptor

Perf/helper shader staging