HTML Widgets and Portals; New widget.IsAuthenticated method added

A new widget.IsAuthenticated() method added (or, in Portals, this can be aliased as page.IsAuthenticated() to ensure the user is still signed in.

This can be used by Widgets before making a call to their Script Code, e.g., in a Widget such as the system-supplied "User Dashboard 1" Widget which polls every so often to update the information displayed.

This minimised the number of warning notifications that Users may receive in finPOWER Connect Cloud.