SFC-UI - several fixes and improvements

+ Updated SFF table view
+ Fixes in SFF create/edit dialog
+ All select boxes can now be reset to no value selected (initial state)
+ Classifier create/edit dialog ehancements

Change-Id: Ib2cfaa097644bd1ccc63591f6c9cca5cb3b1b099
Signed-off-by: Andrej Kincel <akincel@cisco.com>
Signed-off-by: Martin Lauko <malauko@cisco.com>