WICKET-5528 Allow models of subtypes of Select type parameter in SelectOption constructor

(cherry picked from commit 4fe4c999d26a1203b17f96a90b072b8593d3b726)
WICKET-5532 NPE calling PackageResource.getResourceStream() if there is no RequestCycle defined

Use empty request and response when a PackageResource is used out of a request cycle

(cherry picked from commit ae44d26db32587f4ddb9b8c52460ec1450dc96f5)