Split out viewport handling into its own message handler (#3331)

* extract viewport handeling

* fix web overlays

* some cleanup

* remove some physical conversions

* fix resize snapping

* fixup

* apply some review feedback

* make viewport api more ergonomic

* fix

* fix web overlay canvas clear size

* clear workaround for canvas

* rename trigger message

---------

Co-authored-by: Dennis Kobert <dennis@kobert.dev>

editor/src/messages/frontend/frontend_message.rs

@@ -350,6 +350,12 @@ pub enum FrontendMessage {
 	UpdateViewportHolePunch {
 		active: bool,
 	},
+	UpdateViewportPhysicalBounds {
+		x: f64,
+		y: f64,
+		width: f64,
+		height: f64,
+	},
 	#[cfg(not(target_family = "wasm"))]
 	RenderOverlays {
 		#[serde(skip, default = "OverlayContext::default")]