refactor: reviewer's comments

- don't pass `closeAccountMenu` to AccountMenu, instead create it in Account menu state and use it
- add event observers as per original code
- move some variables into component's state (even if they don't need to have setters sometimes)

app/assets/javascripts/ui_models/app_state/account_menu_state.ts

@@ -1,29 +1,58 @@
-import { action, makeObservable, observable } from "mobx";
+import { action, computed, makeObservable, observable, runInAction } from 'mobx';
+import { ContentType } from '@node_modules/@standardnotes/snjs';
+import { WebApplication } from '@/ui_models/application';
+import { SNItem } from '@node_modules/@standardnotes/snjs/dist/@types/models/core/item';
 
 export class AccountMenuState {
   show = false;
   signingOut = false;
+  notesAndTags: SNItem[] = [];
 
-  constructor() {
+  constructor(
+    private application: WebApplication,
+    appEventListeners: (() => void)[]
+  ) {
     makeObservable(this, {
       show: observable,
       signingOut: observable,
+      notesAndTags: observable,
 
       setShow: action,
       toggleShow: action,
       setSigningOut: action,
+
+      notesAndTagsCount: computed,
     });
+
+    appEventListeners.push(
+      this.application.streamItems(
+        [ContentType.Note, ContentType.Tag],
+        () => {
+          runInAction(() => {
+            this.notesAndTags = this.application.getItems([ContentType.Note, ContentType.Tag]);
+          });
+        }
+      )
+    );
   }
 
   setShow = (show: boolean): void => {
     this.show = show;
-  }
+  };
+
+  closeAccountMenu = (): void => {
+    this.setShow(false);
+  };
 
   setSigningOut = (signingOut: boolean): void => {
     this.signingOut = signingOut;
-  }
+  };
 
   toggleShow = (): void => {
     this.show = !this.show;
+  };
+
+  get notesAndTagsCount(): number {
+    return this.notesAndTags.length;
   }
 }

app/assets/javascripts/ui_models/app_state/app_state.ts

@@ -96,7 +96,10 @@ export class AppState {
       application,
       this.appEventObserverRemovers
     );
-    this.accountMenu = new AccountMenuState();
+    this.accountMenu = new AccountMenuState(
+      application,
+      this.appEventObserverRemovers
+    );
     this.searchOptions = new SearchOptionsState(
       application,
       this.appEventObserverRemovers