Highlights in 2D

[lpatiny]

Currently, we can assign 1D from a 2D spectrum, which is great !

We can also, when we hover a line, highlight the corresponding atom.

I think, however, that in the future, we will assign less and less 2D zones, and the issue is that currently, when we hover a 2D zone, we don't see the corresponding assigned 1D atoms.

I would change the propagation of the events.

If the zone is not assigned (no highlight), we let the event propagate to both horizontal and vertical lines so that both atoms are highlighted when the mouse hovers over a zone, even if the zone itself was not assigned.