Also is_simple, is_valid and extensions like dissolve and nsphere relops.
Add umbrella strategies:
- relate: used in setops, relops, buffer, is_xxx, dissolve, etc.
- index: used in rtree
- io: used in wkt read/write and extensions/shapefile
Replace `point_box_by_side` agnostic strategy with CS-specific strategies.
Fix passing of strategies (no defaults when user-defined strategy is
passed) in places like buffer and distance.
Alter tests accordingly.
- Pass intersection strategy into range_in_geometry and internally get
point_in_geometry strategy.
- Add required intersection strategy passing into overlay and buffer
internals.
- Use envelope strategy in assign_parents.
