Attach geoplate_id to columns

[aazaff]

The columns route should also have a plate_id field.

[jczaplew]

How should situations in which a column crosses the boundary of two plates be handled?

[aazaff]

Ideally the columns should be redrawn not to cross geoplate boundaries. However, we can just return a list of geoplate_ids as an array in the interim.

[cambro]

It would be better to fix the column boundaries.

[aazaff]

We actually have a script to split features by their intersection with gplates (or some other polygon layer) as part of gplates-reconstruct. We could apply that script to algorithmically divide the columns. Though this might create very small "residual" columns from columns that only barely overlapped with another plate. This could be especially problematic near the coasts.

[aazaff]

I withdraw this issue because there are so many different plate models out there that there's no reason for Macrostrat to build a stance on this in.