Fragment identity capabilities are incorrectly wrapped

The osgi.identity capability is not a payload capability for a fragment. We must never wrap them as if they are payloads for the hosts they are attached to.

The Cadidates.processCandidates method is currently wrapping all capabilities from a fragment. Also the Candidates code makes the incorrect assumption that a a fragment wiring only has required wires in the osgi.wiring.host namespace. This is not true since osgi.ee namespace is also not a payload requirement.