ENYO-2262: In Inspector, "Frequent" should display properties marked useful as well as the modified properties

Ready for review.

Summary:
- pull in ENYO-2257: Unable to modify property in Inspector: Uncaught TypeError: no method 'setProperty'
- display properties marked useful when FREQUENT filterLevel is active
- display modified properties when FREQUENT filterLevel is active

Enyo-DCO-1.1-Signed-off-by: Marie-Antoinette de Bonis-Hamelin (Marian)
marie-antoinette.de-bonis-hamelin@hp.com