Is your feature request related to a problem? Please describe.

cuSpatial has separate APIs for bounding boxes for trajectories, polygons, and linestrings. These all duplicate code that uses reduce_by_key to compute the bounds of groups of points.

Ultimately, we should be able to call .bounds() on a GeoSeries, regardless of the contents. To enable this, we should build consistent C++ APIs for this function to call.

Describe the solution you'd like

Start by providing a C++ function to compute the bounds of groups of points. This can be reused to compute the bounds of any geometry -- only the offset / ID computation needs to differ for different geometries.