LPS-45733 Improper PortletDataContext state bug fix

Hey Brian,

This is a bug fix, and @danielkocsis had to reorganize the methods a bit. The bug was that the PortletDataContext had an improper setup and the validation failed due to this fact. The solution was to validate before the PDC is being created, doing this the PDC will be alway a valid state of the export/import process.

Thanks,

Máté