rust/sedona-spatial-join: Enable KNN join for Geography

[paleolimbot]

Currently we don't do support a KNN join for the Geography type. To make this work we have to:

• Ensure that the duplicate rectangles inserted into the index are considered correctly (right/left side of the antimeridian), which may mean some additional deduplication.
• Ensure we can push the distance calculation into the KNN query. The distance metric is possibly not what we want here (s2geography's distance calculation is possibly faster and the geo dependency in geo-index is causing dependency issues).
• Add the KNN predicate to the list of supported predicates in the geography join planner.