Add the possibility to filter local to broadcast/multicast traffic

[MatteoBiscosi]

Add the possibility to filter the flows, going from local to broadcast/multicast traffic (similar to local to local):

Add a new entry in that dropdown that gives the possibility to filter flows in a way that only flows going from local to broadcast/multicast are displayed.
Remember that the http_lint function that handles the filtered parameter needs to be changed, otherwise the parameter will be deleted for security reason.

[MatteoBiscosi]

not considered useful right now