Handle more join types and expressions for Point in Polygon

[halfabrane]

This PR adds the following join and expression support for Point in Polygon joins

• [x] Left Outer Join now uses Spatial Index eg.

          points.join(polygons, "left-outer", $"point" within $"polygon")

• [x] We can rewrite queries to use Spatial Index even when complex filters are added, eg.

       points.join(polygons).where($point within $polygon).filter(any cond)

[codecov-io]

Codecov Report

Merging #202 into master will decrease coverage by <.01%. The diff coverage is 100%.

@@           Coverage Diff            @@
##           master   #202      +/-   ##
========================================
- Coverage      90%    90%   -0.01%     
========================================
  Files          52     52              
  Lines        1791   1790       -1     
  Branches      125    129       +4     
========================================
- Hits         1612   1611       -1     
  Misses        179    179

Impacted Files	Coverage Δ
src/main/scala/magellan/catalyst/SpatialJoin.scala	97.61% <100%> (-0.06%)	:arrow_down:

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