Dev Tooling metric: Drips streams from other dev tools

[ccerv1]

What is it?

This metric would count the number of distinct Drips streams from other known artifacts to a given repo. It would require us to create a funding event_type for establishing a stream and then running a count distinct on the from_ids for all such events. This would be greatly facilitated by having a Drips data source instead of doing our own indexing.