[Lens] Support metric vis title

[drewdaemon]

Describe the feature:
We would like to give users the ability to set a title for an entire metric vis.

This title will be displayed from within the metric visualization itself but we may give users the option to configure this title from both the dashboard and the Lens editor.

Describe a specific use case for the feature:
A visualization such as this would benefit from having an informative title to orient the user to the meaning of the two-letter labels.

@elastic/charts related issue
elastic/elastic-charts#1862

[elasticmachine]

Pinging @elastic/datavis (Team:DataVis)

[elasticmachine]

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

[drewdaemon]

Another option we discussed was simply to hide the panel title by default, but allow the user to set a title at the dashboard level all the same.

cc: @ghudgins

[philippkahr]

Any update on this? Seems weird that every panel supports a title but the new metric visualisation doesn't.

[flash1293]

@markov00 @gvnmagni is there anything merged on elastic-charts side for this yet?

[markov00]

Not yet but we can add this in our roadmap

[drewdaemon]

Relevant discussion with a user who is setting the primary metric dimension name to a ' ' to hide it #145308 (comment)

[ThomThomson]

I'm curious why we don't look towards using the existing Dashboard titling function, and just updating the styling of it to match?

[gvnmagni]

Your point is very valid @ThomThomson. I believe there is also a wider discussion around the fact that the tile should be part of shouldn't be part of the chart and therefore available and editable in Lens. I'm not sure of the technicality behind this but I'm afraid we have to consider that as well

[markov00]

More than a technical problem is mostly a design concern: we have the hope that we can nicely align titles across charts, but each chart could have some small differences in how a title is rendered: some titles could be limited in width by some icons/text represented on the right side, in others, we can limit the number of rows a title can be rendered in others we allow subtitles, etc.
In practice, the title is not just a stratification of a text block on top of a chart block, but the title becomes part of the visualization too.

Consider also that, in the near future, we are interested in bringing more info into the title, like dynamic titles (where we can reuse chart colors, and values to improve the title and reduce the use of axis titles) and we like to share these capabilities as part of the embeddable/Lens visualization and not a Dashboard only feature.

[stratoula]

Closing this in favor of #149675

We are going to support it for all Lens charts