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

frontend/src/utilities/js-message-dispatcher-binding.ts

@@ -0,0 +1,4 @@
+// This file is instantiated by wasm-bindgen in `/frontend/wasm/src/lib.rs` and re-exports the `handleJsMessage` function to
+// provide access to the global copy of `js-message-dispatcher.ts` with its shared state, not an isolated duplicate with empty state
+
+export { handleJsMessage } from "@/utilities/js-message-dispatcher";