WellLogViewer - Option to hide depth-readout from viewer overlay

[Anders2303]

The Well-log viewer renders a small black box with the currently hovered or pinned log depth. This element is currently not needed for our use webviz, so it would be nice if there was an option that allowed us to disable it (for now, we're applying CSS to remove it).

[w1nklr]

One possibility is to have a callback props.
IMO; there are 2 possible strategies:

1. Props is callback only
   If callback is provided, use it.
   If none, use no readout.
   The API should provided a default callback implementation.

2. Props is bool | callback
   If callback is provided, use it.
   If boolean, display or hide default implementation.