Privacy invading collection of telemetry-dashboard usage

Sending an event to analytics whenever somebody clicks button or changes the state will allow us an idea about which features and default values are should be reconsidered...

More importantly it'll also tell us which measures and filters people use often use. This can be useful when arguing about measure retirement from firefox or considering which filters to maintain. Perhaps, we'll find that a different default filter would be appropriate.

Note, we'll have to sacrifice privacy of firefox developers, but I think that's an acceptable evil in this case :)