[Maps] Global fit data to bounds option

[alexfrancoeur]

In the Maps app today, we have layer specific "fit data to bounds" options. However, with the ability to search and filter across multiple layers (and dashboard embeddability options in the future), it'd be great if we could fit data to bounds on a global level. Similar to the control seen in region and coordinate maps.

[elasticmachine]

Pinging @elastic/kibana-gis

[alexfrancoeur]

@nreese I would love to see this as a control. But for the embeddability use case, it'd be interesting to have a global config that is just "automatically fit to data". That way, when a map is embedded any filters applied to the dashboard will automatically fit to the map. This could kill two birds with one stone (#2054)

[alexfrancoeur]

@thomasneirynck this would be a good addition to the new "tools" menu

[thomasneirynck]

this might be a little tight, but now that ES supports the geo_bounds agg, we can introduce this. I put on 7.8 label, just to indicate priority.