Describe the bug
When using TooltipType.Crosshair the horizontal line remain visible also when the pointer is outside the chart area.

To Reproduce
Steps to reproduce the behavior:

1. Configure a simple chart with the following settings:

<Chart>
  <Settings tooltip={TooltipType.Crosshairs} />
  <BarSeries
    id={'bar'}
    xScaleType={ScaleType.Time}
    yScaleType={ScaleType.Linear}
    xAccessor={0}
    yAccessors={[1]}
    data={KIBANA_METRICS.metrics.kibana_os_load[0].data}
  />
</Chart>

2. Move the mouse over the chart to see the crosshair line
3. Move the mouse outside the chart, the crosshair line remain visible on the top of the chart

Expected behavior
If the pointer is outside the chart, than the crosshair line should be hidden

Screenshots

Version (please complete the following information):

• Elastic Charts: 15.x