Add public API test to Quick API.

This test checks the compatibility of WebEngineView and QtWebKit's
WebView. (The differences are marked as expected failure.)

The QQuickWebEngineNavigationRequest class has not been
implemented yet.

Change-Id: Ie03d605b06d141c6ca352ae1cd5c6a38f4c80039
Reviewed-by: Andras Becsi <andras.becsi@digia.com>
Reviewed-by: Jocelyn Turcotte <jocelyn.turcotte@digia.com>