Cache Vello render output as stitchable textures (#3722)

* WIP render caching

* Hook up render cache to render pipeline

* Fixed offsets

* Initial cleanup

* Integrate cache with context invalidation

* Cleanup

* Improve rounding and reduce tile size to fix vello not rendering

* Include pointer position in cache key

* Avoid unwraps and zero sized textures

* Destroy textures after blitting to surface

* Fix context dependencies

* Exclude footprint from render params

* Batch animation frame messages

* Add vello max render size to preference dialogue

* Remove unused import

* Reorder vello preference

* Clean up preferences dialog

* Apply review suggestions

* Cap max render region size

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Co-authored-by: Keavon Chambers <keavon@keavon.com>

Cargo.lock

@@ -2307,6 +2307,7 @@ dependencies = [
  "wasm-bindgen",
  "wasm-bindgen-futures",
  "web-sys",
+ "wgpu",
  "wgpu-executor",
 ]