Add the ability to control the size of markers

[dekabrsky]

The task is to place markers on a line chart. We are satisfied with the behavior, as in the first picture, when the size of the dot is proportional to the thickness of the line. However, in certain cases I need to stretch a small number of dots to fit the entire width of the screen. In this case, the library increases the points to some size, and they become huge. Can I somehow disable or control this scaling mechanism? I've seen the size option on the SeriesMarker, but it only allows to scale what's already drawn in such an enlarged scale.