Refactor ZenStartup.mjs and zen-settings.js

- Refactor ZenStartup.mjs to use gZenKeyboardShortcutsManager instead of gZenKeyboardShortcuts.
- Refactor zen-settings.js to use async/await for _resetCKS and _handleKeyDown functions.

src/browser/base/content/ZenStartup.mjs

@@ -45,7 +45,7 @@
         gZenUIManager.init();
         gZenVerticalTabsManager.init();
         gZenCompactModeManager.init();
-        gZenKeyboardShortcuts.init();
+        gZenKeyboardShortcutsManager.init();
 
         function throttle(f, delay) {
           let timer = 0;

src/browser/components/preferences/zen-settings.js

@@ -714,18 +714,18 @@ var gZenCKSSettings = {
     }
   },
 
-  _resetCKS(input, key) {
+  async _resetCKS(input, key) {
     input.value = 'Not set';
     input.classList.add('zenCKSOption-input-not-set');
     input.classList.remove('zenCKSOption-input-invalid');
-    gZenKeyboardShortcuts.setShortcut(key, null);
+    await gZenKeyboardShortcuts.setShortcut(key, null);
   },
 
   _initializeEvents() {
     window.addEventListener('keydown', this._handleKeyDown.bind(this));
   },
 
-  _handleKeyDown(event) {
+  async _handleKeyDown(event) {
     if (!this._currentAction) {
       return;
     }
@@ -747,12 +747,12 @@ var gZenCKSSettings = {
       input.blur();
       return;
     } else if (event.key === 'Backspace' && shortcutWithoutModifiers) {
-      this._resetCKS(input, this._currentAction);
+      await this._resetCKS(input, this._currentAction);
       return;
     }
 
     if (!shortcut.ctrl && !shortcut.alt && !shortcut.shift && !shortcut.meta) {
-      this._resetCKS(input, this._currentAction);
+      await this._resetCKS(input, this._currentAction);
       return; // No modifiers, ignore.
     }
 
@@ -765,7 +765,7 @@ var gZenCKSSettings = {
     }
 
     event.preventDefault();
-    gZenKeyboardShortcuts.setShortcut(this._currentAction, shortcut);
+    await gZenKeyboardShortcuts.setShortcut(this._currentAction, shortcut);
 
     input.value = gZenKeyboardShortcuts.shortCutToString(shortcut);
     input.classList.remove('zenCKSOption-input-not-set');