Is your feature request related to a problem? Please describe.
Some series may have orphan data points, points that are between two null datums like:

[
   ...,
   {x: 1, y: null},
   {x: 2, y: 10},
   {x: 3, y: null},
   ...,
]

When a series has orphan data points like the example above, we need to find a way to display the single point value.

Fitting functions (#55) can fill the gaps with specific values (like adding zeros or an average value), but the developer or user can decide to keep null values.

Describe the solution you'd like
If the style of the line/area already shows single circles as data points we don't need to add anything to that rendering.

If the style configuration hides the data points we need to force displaying these points when orphans.

We also have to configure the line/area path generation defined function to correctly specify when a line/area is not defined: https://github.com/d3/d3-shape#line_defined https://github.com/d3/d3-shape#area_defined

Kibana Cross Issues
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• every related Kibana issue is listed under Kibana Cross Issues list
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