[Lens] Allow min/max on dates for visualizations that support dates as metrics

[a03nikki]

Describe the feature:
Add minimum and maximum function options on dates

Describe a specific use case for the feature:
When I was trying to create a dashboard that displayed the min(@timestamp) and max(@timestamp) as it I wanted to make clear the date range that had data and also include it in the generated PDF to share. However, I found the functionality is not available in Lens.

It would be nice to line up multiple metrics in a single visualization, but the real missing feature is the Minimum and Maximum functions are not available on date field types.

Lens

Aggregation Based Metric

(Screenshots are from Kibana 7.11.0 using the sample data set of logs.)

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[a03nikki]

This also applies to tables in Lens v7.16

• Legacy aggs
  
• New Lens