chore(geopandas): Write sjoin match tests for dwithin()

[petern48]

Our test suite for joins is quite poor at the moment. Now that I look at it, it's generally just testing if it's hooked up and not if the exact results...

https://github.com/apache/sedona/blob/1eb5769be3b1ab7266a9dcecc6e3407ba28ab57a/python/tests/geopandas/test_sjoin.py#L171-L183

test_match_geopandas_series.py has proved to be super helpful for finding bugs in Sedona. We should replicate this for joins. In this recent PR fix to ST_Distance, there's some suspicion that it's possible distance join is buggy on an edge case. Comparing results with geopandas would be a great way to test this.

Afterwards, we should also improve our tests for the rest of sjoins and for sindexes.