Lazy filtering of empty partitions after spatial filters

When we apply a filter (cone, polygonal or box), we may carry empty partitions in the catalog for the remainder of the computations but we can reduce its likelihood.

Here is a small example of applying a cone search to a catalog. It doesn’t make sense to keep the entire patch of sky covered by partitions 1 to 4 because they have large regions where they won’t overlap with the filter. By increasing the order of partitions 1 to 4 we can remove the regions of each partition around the filter that we won’t need.

No files or tests are named. Start by tracing how cone, polygonal, and box filters select catalog partitions, then determine how partition order can reduce regions that do not overlap the filter. Done means spatial filtering avoids carrying unnecessary empty partition regions through later computations.

Written by the indexing model from the issue text.