Use a pre-defined limit for loading stac-geoparquet

[gadomski]

Folks are going to load in a bunch of items via stac-geoparquet, and we probably don't want to render them all. We should have a configurable upper limit — 10,000 feels like a decent first pass, but I'm open to other suggestions on the number.

My thought is that the limit could go in the Filter section, as a slider under nearth datetime: