fix(typescript): Fix TableTooltip and LineComputedSerieDatum-type on line

[johnolos]

Slight fix for TableTooltip, sorry about that.

Also, I found LineComputedSerieDatum useful exported subtype when creating custom layers upon Line. Basically for when customizing computedData with additional effects.

  getCustomLayer = (props: CustomProps) => {
    const { xScale, yScale, computedData } = props;
    const areaGenerator = area<LineComputedSerieDatum>()
      .x(d => xScale(d.data.x))
      .y0(() => yScale(0))
      .y1(d => yScale(d.data.y))
      .curve(curveMonotoneX);
    ...
    return <path
        ...
        d={areaGenerator(data)}
      />;
  };

@plouc How accepting would you be of a PR adding defs to Line?
Line isn't using it directly, but custom layers might, and therefore it would be helpful to add patterns to the main SVG element.

Work-around is to have a seperate svg element with pattern defined in the custom layer itself.

[plouc]

@johnolos defs definition should be defined inside the core package IMO

[johnolos]

@plouc Fair. I'll leave it for now.

[plouc]

Thank you for your contribution @johnolos