Auto-apply facets?

[Robsteranium]

The UR found that people tended to click to onto the next facet without clicking apply. They might be more used to a figure-it-all-out-upfront wizard...

We could automatically apply a facet when someone clicked on a different one. This would also help to demonstrate what's happening (as the dataset results table would get updated) as they go.

In theory we could remove the apply control altogether and update the table for every interaction. This would be fine for codelist-only selections (as we have now) but would probably be too expensive once we've got finer-grained code selections.