Filter by networks globally

[tmaiaroto]

There are a few global filters for the dashboards. Time (date range) is the most important one, but also social networks. This should just be a button up top near the date range that drops down (or fades in) another row/bar that has each social network icon with a checkbox (or dim them when not active) that lets users select which networks to filter the dashboard results by.

All API endpoints are setup to accept a comma separated list of networks as a parameter. It is a common query condition.