Previously, all widgets would be listed in accesskit as children of the
toplevel window.
With this change, they will be reported as child of the `egui::Window`
they are in, Which should increase parseability of the ui for
screenreaders and integration tests.
Added an accesskit test to check that it is indeed working.
Co-authored-by: Wybe Westra <w.westra@kwantcontrols.nl>