Event broadcasting system (#692)

* broadcast system implemented but not everywhere

* unused types

* code review with keavon

* - optional signal mappings
- tool.rs simplification

* Cleanup

* reduced code duplication in `tool.rs`

* ran cargo fmt

* code review changes

* fix merge error

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

frontend/wasm/src/editor_api.rs

@@ -112,6 +112,9 @@ impl JsEditorHandle {
 		let message = PortfolioMessage::UpdateDocumentWidgets;
 		self.dispatch(message);
 
+		let message = PropertiesPanelMessage::Init;
+		self.dispatch(message);
+
 		let message = ToolMessage::InitTools;
 		self.dispatch(message);