feat: Implement ST_Crosses and ST_Overlaps predicates

[petern48]

Here's my original commit that added the geos (library) implementation of the other predicates. Implementing ST_Crosses and ST_Overlaps should be as simple as pattern matching (just a library call), whatever spots you see other predicates (e.g ST_Intersects, ST_Within, etc)

42cca94

For whoever picks this up, please let us know if you run into differences in behavior between the Rust implementations and PostGIS.

Part of #174