[Lens] Split chart support (aka. Facet, Trellis, Small multiples)

[th0ger]

Lens should support what's often called a Facet chart/grid (ggplo2t), Trellis Chart, or Small Multiples chart.

For the traditional visualizations, this was partially supported via "split chart" by "Rows" and/or "Colums", but they do not exist for Lens. (And I could not find any issues on this.)

It is currently possible to get a "facet feeling", by arranging visualizations in a grid on a dashboard, but there are many drawbacks, such as:

• Repeated borders take up extra space.
• Repeated legends/ticks take up space.
• x/y axes can't auto-scale together across visuals.
• Facet categories must be hardcoded (does not support dynamically changing values).
• Lots of manual configuration.
• Performance (query run n*m times?).

[elasticmachine]

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

[flash1293]

Thanks for opening this issue, I agree this is something we should offer.

[flash1293]

I just realized there's another issue tracking the same thing - closing this one as a duplicate: #72063

[th0ger]

Thanks, @flash1293 I looked for existing issues, but didn't find that one.