Display Asterisk on Unsaved Documents (#392)

* ability to mark an open document as unsaved

* unsaved detection now being triggered based on layer tree height

* - 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

frontend/wasm/src/api.rs

@@ -88,7 +88,7 @@ pub fn select_document(document: usize) {
 
 #[wasm_bindgen]
 pub fn get_open_documents_list() {
-	let message = DocumentsMessage::GetOpenDocumentsList;
+	let message = DocumentsMessage::UpdateOpenDocumentsList;
 	dispatch(message);
 }