Column view summary stats

[davidsklar99]

Column view does not have summary stats (https://dev.macrostrat.org/columns/802, compare https://macrostrat.org/sift/#/column/802).

Most notable here are lack of area and thickness, but other summaries, like environment/fossils also possibly useful. Of course big improvement is nice column rendering. Ideally some (fossils especially, but also our own measurements and SGP samples/measurements) would be represented in the column; the “Myr” callout for gap duration needs a label: “33.2 Myr hiatus” or something, otherwise many will infer that number being the age at that point.