feat: Nativize "No distraction" theme as "Focus Mode" (#758)

Co-authored-by: Mo Bitar <me@bitar.io>

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

@@ -3,14 +3,17 @@ import { action, makeObservable, observable } from 'mobx';
 export class QuickSettingsState {
   open = false;
   shouldAnimateCloseMenu = false;
+  focusModeEnabled = false;
 
   constructor() {
     makeObservable(this, {
       open: observable,
       shouldAnimateCloseMenu: observable,
+      focusModeEnabled: observable,
 
       setOpen: action,
       setShouldAnimateCloseMenu: action,
+      setFocusModeEnabled: action,
       toggle: action,
       closeQuickSettingsMenu: action,
     });
@@ -24,6 +27,10 @@ export class QuickSettingsState {
     this.shouldAnimateCloseMenu = shouldAnimate;
   };
 
+  setFocusModeEnabled = (enabled: boolean): void => {
+    this.focusModeEnabled = enabled;
+  };
+
   toggle = (): void => {
     if (this.open) {
       this.closeQuickSettingsMenu();