Auto display custom labels

[lpatiny]

Currently it can be very confusing if the custom atoms labels are not displayed and you try to add some. Nothing happens (apparently).

If we add a custom atom label we should toggle the visualization of the custom atom labels for this specific molecule.

Not sure how to implement this. Any callback to know a custom atom label was added / modified / removed ?

@tpoisseau any suggestions ?

[tpoisseau]

I think if custom labels are hidden, quickNumbering should be disabled.
Today there is no props to prevent quickNumbering. I let you create an issue in react-ocl to implement this feature if you agree with me.