Update variant descriptions if variant node names change

[mattbrailsford]

When using the variant property editor at the point you define the variants, it fetches the info from the related variant nodes, however, once these variants are created, the name never updates so if one of the variant node names changes, the variant in the prop editor remains the same and requires it to be removed / re-added in order for it to update.

The node names should probably attempt to dynamically resolve where possible.