Console: the "no metric" stream width scaling needs tweaking

The scaling for a stream lacking metrics needs tweaking (e.g., the stream between the filter and peek: `... -> filter -> peek` ; no sink).

The width of such a stream can end up being much larger than streams that have a larger actual flow. A good heuristic for this case is: #output tuples == #input tuples.

This can easily be demonstrated by the SensorAnalyticsApplication sample, where there are widely disparate tuple flow rates – e.g., 1k/sec and 1/sec.