Feature request: More flexibility for scatter plots

[mikealchex]

Is your feature request related to a problem? Please describe.

Hi there!

It'd be amazing to plot scatter plots with more flexibility.

Right now I'm using the combination of

    lineVisible: false,
    pointMarkersVisible: true,

for a lineSeries and this has two drawbacks:

1. Prevents me from specifying a custom size to each marker
2. Giving each point a different color results in a bug where only the first points with the same color are drawn.

Describe the solution you'd like

An easy way to draw scatter plots with custom color and size control per points.