[Maps] Style icon based on term value

[alexfrancoeur]

Today, you are only able to style a point on a map based on a metric. In some cases, I'd like to style this based on a term. Yes, there are certainly some workarounds to manipulate this on the ingest side but it'd be nice to not have to do that.

In the below example, I'm tracking live flights. I'd like to be able to color the flight red if it's been grounded and green if it's in the air. Ideally, a UI that lets me choose a field value and what to color if it equals that value would be ideal.

[elasticmachine]

Pinging @elastic/kibana-gis

[nreese]

Closing, duplicate of #32202