Welcome screen, refactor to allow zero documents, and add TS typing to widgets (#702)

* unfinished implementation

* Add frontend for the empty panel screen

* Add an icon for Folder based on NodeFolder

* fixed messages causing peicees of ui not to render on new document

* Standardize nextTick syntax

* WIP generisization of component subscriptions (not compiling yet)

* Fix crash when loading font and there is no active document

* Only advertise tool actions with a document

* Fix failure to create new document

* Initalise the properties panel

* Fix highlight tab, canvas jump, warns and layer tree

* Fix tests

* Possibly fix some things?

* Move WorkingColors layout definition to backend

* Standardize action macro formatting

* Provide typing for widgets in TS/Vue and associated cleanup

* Fix viewport positioning initialization

* Fix menu bar init at startup not document creation

* Fix no viewport bounds bug

* Change !=0 to >0

* Simplify the init system

Closes #656

Co-authored-by: Keavon Chambers <keavon@keavon.com>
Co-authored-by: 0hypercube <0hypercube@gmail.com>

editor/src/frontend/frontend_message.rs

@@ -17,7 +17,7 @@ pub enum FrontendMessage {
 	// Display prefix: make the frontend show something, like a dialog
 	DisplayDialog { icon: String },
 	DisplayDialogDismiss,
-	DisplayDialogPanic { panic_info: String, title: String, description: String },
+	DisplayDialogPanic { panic_info: String, header: String, description: String },
 	DisplayEditableTextbox { text: String, line_width: Option<f64>, font_size: f64, color: Color },
 	DisplayRemoveEditableTextbox,
 
@@ -30,6 +30,7 @@ pub enum FrontendMessage {
 	TriggerIndexedDbWriteDocument { document: String, details: FrontendDocumentDetails, version: String },
 	TriggerPaste,
 	TriggerRasterDownload { document: String, name: String, mime: String, size: (f64, f64) },
+	TriggerRefreshBoundsOfViewports,
 	TriggerTextCommit,
 	TriggerTextCopy { copy_text: String },
 	TriggerViewportResize,
@@ -58,5 +59,5 @@ pub enum FrontendMessage {
 	UpdatePropertyPanelSectionsLayout { layout_target: LayoutTarget, layout: SubLayout },
 	UpdateToolOptionsLayout { layout_target: LayoutTarget, layout: SubLayout },
 	UpdateToolShelfLayout { layout_target: LayoutTarget, layout: SubLayout },
-	UpdateWorkingColors { primary: Color, secondary: Color },
+	UpdateWorkingColorsLayout { layout_target: LayoutTarget, layout: SubLayout },
 }