Configurable columns

[narc0tiq]

YARM is very wide, especially when fully expanded to show all the sites. It should be possible to configure only a subset of columns to be shown at a time (possibly also with presets?).

With #11, columns should be configurable separately per filter, so that, e.g., the "low resource remaining" filter will only show site name, percent remaining, and ETD, while the "all sites" filter can show all columns.

[narc0tiq]

This will actually be in 1.0 at least partially -- we had a compact mode (YARM-toggle-lite) for a while but it's been refactored into actual (albeit fixed) column layouts. The step from there to making the columns configurable is not that far, although it will take a bit more to support the surface split correctly.