[Lens] Leverage time series metric metadata for smarter defaults

[ghudgins]

Describe the feature: When using pure mode: time_series data views, dragging a metric field (with extra metadata about the type of metric) should default to the proper aggregation.

Default aggregations:

• Rates --> Rate + (Sum / Min / Max/ Average) <-- need to decide which one
• Gauge --> Average (so it works with downsampling)

Default vis:

• do we want to make any changes? Does line vis make more sense for time series data?

Describe a specific use case for the feature:
When I am dragging out a rate metric
I need Lens to pick "Counter Rate" by default
So I can see my rate with the proper aggregation by default (avoiding clicks)

[elasticmachine]

Pinging @elastic/kibana-vis-editors @elastic/kibana-vis-editors-external (Team:VisEditors)

[flash1293]

To discuss - should gauge metrics default to average instead to make sure it works will rollups?

[timductive]

this support has been added