feat: Add BrowserWindow.setWindowButtonVisibility()

Fixes #12701 and supersedes #13131.

Ideally we would have added `setTitleBarStyle()`, but that is a
significantly more involved change. For example, consider the case where
we switch from `hidden` to `normal`. We would not only have to show the
traffic light buttons, we would also have to switch the window from a
frameless to a framed window and deal with various other window state.
Lets instead implement a simple solution for #12701.

atom/browser/native_window.cc

@@ -355,6 +355,10 @@ bool NativeWindow::IsMenuBarVisible() {
   return true;
 }
 
+bool NativeWindow::SetWindowButtonVisibility(bool visible) {
+  return false;
+}
+
 double NativeWindow::GetAspectRatio() {
   return aspect_ratio_;
 }