Keep the shape-to-tile grid zoom-only while scaling GPU paint by DPR
(capped at 1024px). Fix fractional browser zoom and pan, cap atlas slots
with eviction instead of panic, and split paint vs view scale with
explicit paint/atlas/screen tile sizes.
* ♻️ Move shape type serialization to wasm module
* ♻️ Refactor serialization of constraints and vertical alignment into wasm module
* ♻️ Refactor serialization and model of shape blur
* ♻️ Refactor bool serialization to the wasm module
* ♻️ Split wasm::layout into submodules
* ♻️ Refactor serialization of AlignItems, AlignContent, JustifyItems and JustifyContent
* ♻️ Refactor serialization of WrapType and FlexDirection
* ♻️ Refactor serialization of JustifySelf
* ♻️ Refactor serialization of GridCell
* ♻️ Refactor serialization of AlignSelf
* 🐛 Fix AlignSelf not being serialized
* ♻️ Refactor handling of None variants in Raw* enums
* ♻️ Refactor serialization of grid direction
* ♻️ Refactor serialization of GridTrack and GridTrackType
* ♻️ Refactor serialization of Sizing
* ♻️ Refactor serialization of ShadowStyle
* ♻️ Refactor serialization of StrokeCap and StrokeStyle
* ♻️ Refactor serialization of BlendMode
* ♻️ Refactor serialization of FontStyle
* ♻️ Refactor serialization of GrowType