All the demos so far focus on show value on hover, but a demo should be created where multiple scatter plots are plotted on top of each other and the mouse can hover and/or click to select a single line by clicking on it. This idea came from a question in #470

On one hand custom mouse-aware plottables could be used here (#414, @Benny121221), but on the other hand it would be nice to have this functionality with common plottables (like scatter and signal).