ui: details tooltip picks out uneven data points

[couchand]

It looks like the details tooltip just picks out the closest datapoint in each series to the cursor, which has very unintuitive behavior around series for started/stopped nodes. Example:

The first recorded datapoint for nodes that were started minutes later is picked up when hovering over the start of this chart (which you can see by the huge dot that gets added to the hovered points), which makes it seem like, for instance, n5 had 19 replicas at 16:28, when in fact it didn't exist.

[github-actions]

We have marked this issue as stale because it has been inactive for
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or adding a comment will keep it active. Otherwise, we'll close it in
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