[Meta] Borealis theme checklist

[markov00]

A checklist for the new borealis theme update

• Verify that chart tooltips are rendered with the right theme/style (in particular check the Visualize "detailed" tooltip)
• Verify that the chart background correspond to the right theme mode (grey,blue,light)
• Verify the color of the focus ring in dark/light mode in the Color Mapping color picker

[elasticmachine]

Pinging @elastic/kibana-visualizations (Team:Visualizations)

[ghudgins]

@markov00 is this a dupe of #192814