Mark project as edited via MakeCode editorChange callback (#611)

Alternative to relying on editor being opened.

---------

Co-authored-by: Robert Knight <[email protected]>

Author: microbit-grace

src/store.ts

@@ -406,10 +406,8 @@ const createMlStore = (logging: Logging) => {
 
           setEditorOpen(open: boolean) {
             set(
-              ({ download, model }) => ({
+              ({ download }) => ({
                 isEditorOpen: open,
-                // We just assume its been edited as spurious changes from MakeCode happen that we can't identify
-                projectEdited: model ? true : false,
                 download: {
                   ...download,
                   usbDevice: undefined,
@@ -907,6 +905,8 @@ const createMlStore = (logging: Logging) => {
                   );
                   return {
                     project: newProject,
+                    // We just assume its been edited as spurious changes from MakeCode happen that we can't identify
+                    projectEdited: true,
                   };
                 } else {
                   logging.log(