Rename `colorProvider` setting to `nodeFillColor` about unipept-visualizations

[bmesuere]

Should we add an alias and mark the old name as deprecated as a first step? Because otherwise this will break for existing users.

[pverscha]

Good point, I'll update it as you suggested :)

[pverscha]

After some more investigating, I found out that all settings related to color behave identically to how they behaved in version 1 of the visualizations, except for one: nodeFillColor.

Setting nodeFillColor to (d) => "#00FF00" results to this in v1.0 of the treeview:

And has no effect in v2.0:

This is due to the fact that no fill is set for the nodes in v2.0, which we should fix. I propose that we do not rename the option and that I fix the nodeFillColor setting. All behaviour will then be identical to v1.0

[pverscha]

Fixed in #68.