js: Use templates for non-translatable strings

This reverts commit 9d941f8202 and replaces all additional
instances of .format() that have been added since.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2160>

js/ui/shellMountOperation.js

@@ -564,7 +564,7 @@ var GnomeShellMountOpHandler = class {
     _setCurrentRequest(invocation, id, type) {
         let oldId = this._currentId;
         let oldType = this._currentType;
-        let requestId = '%s@%s'.format(id, invocation.get_sender());
+        let requestId = `${id}@${invocation.get_sender()}`;
 
         this._clearCurrentRequest(Gio.MountOperationResult.UNHANDLED, {});