DialogElement should have a helper method for querying the overlay element #3677
Description
Describe your motivation
If the Dialog has dynamic contents it makes sense to test those contents.
Describe the solution you'd like
There is already a method getOverlay in DialogElement, but it's private. The easiest solution would be to turn it to public.
Describe alternatives you've considered
In a simple use case $("vaadin-dialog-overlay").first() also does the trick.
Additional context
No response