[QtQuick] WebView is not focused in Dialog

Steps to reproduce the issue:
1. Run attached sample project
2. Click the button to open Dialog

Expected outcome:
The web page loads, cursor is blinking in in the search box and user can start typing.

Actual outcome:
The web page loads, cursor is blinking in in the search box, but when user starts typing nothing happens.

Workaround:
Using QML type Window instead of Dialog.