Tighten tooltip placement on single point charts

[nickofthyme]

Is your feature request related to a problem? Please describe.
When a single x value is rendered, the tooltip is placed on the far left or right of the chart as the highlighted area is the full chart area. This causes a non-ideal tooltip placement.

Describe the solution you'd like
A more narrow highlighter and tooltip placement closer to the actual point it is displaying

Describe alternatives you've considered
N/A