This class or its subclass can be set on the
QWebEngineProfile and its API enables intercepting
Chromium's cookies, setting and deleting cookies
in the cookie store.
These functions are asynchronous so if the result
of the task is needed the user can provide a
callback which will be run on the calling thread
when the requested operation finishes.
This does not include a hook for QQuick layer yet,
there we have to figure out what the most convenient
way is from a developer's perspective.

Change-Id: I6a3af071883ce632df7a2fb952da93f306ac3fe2
Reviewed-by: Pierre Rossi <pierre.rossi@theqtcompany.com>