Change responses to use classes instead of interfaces (#394)

* ability to mark an open document as unsaved

* unsaved detection now being triggered based on layer tree height

* Changed responses to use classes instead of interfaces

* - rust implementation of unsaved markers
- upgraded eslint

* updated eslint in package.json

* - Renamed GetOpenDocumentsList -> UpdateOpenDocumentsList
- is not -> was not

* changed hash to current identifier to better reflect its meaning

* resolve some merge conflicts

* removed console.log statement leftover from debuging

* - changed Response to jsMessage
- split files
- Array<> -> []

* -remove path from UpdateLayer

* - remove unused if statements

* - comment for reflect-metadata
- registerJsMessageHandler -> subscribeJsMessage
- readonly message properties
- fixed binding filename and comment
- toRgb -> toRgba

* - newOpacity -> transformer
- added comments

* MessageMaker -> messageMaker

editor/src/frontend/frontend_message_handler.rs

@@ -1,4 +1,4 @@
-use crate::document::layer_panel::{LayerPanelEntry, Path, RawBuffer};
+use crate::document::layer_panel::{LayerPanelEntry, RawBuffer};
 use crate::message_prelude::*;
 use crate::tool::tool_options::ToolOptions;
 use crate::Color;
@@ -15,7 +15,7 @@ pub enum FrontendMessage {
 	DisplayPanic { panic_info: String, title: String, description: String },
 	DisplayConfirmationToCloseDocument { document_index: usize },
 	DisplayConfirmationToCloseAllDocuments,
-	UpdateLayer { path: Path, data: LayerPanelEntry },
+	UpdateLayer { data: LayerPanelEntry },
 	UpdateCanvas { document: String },
 	UpdateScrollbars { position: (f64, f64), size: (f64, f64), multiplier: (f64, f64) },
 	UpdateRulers { origin: (f64, f64), spacing: f64, interval: f64 },