carousel behavior inconsistent

[Nancy-Salpepi]

For phetsims/qa#1014, but will defer until the sim is revisited:

On the Generic screen, the carousel autoscrolls when moving the point along the number line, but this doesn't happen on the Operations screen. I thought it might be nice (and consistent) to have that behavior on the Operations screen as well.

Deferring because this behavior also happens in published.