Add Hilbert Curve Encode and Decode Functions

Why it matters

This feature introduces functions to encode and decode coordinates using the Hilbert Curve, enabling spatial indexing and efficient multidimensional data ordering. It helps users perform spatial queries and optimize storage and retrieval of spatial data by preserving locality.

How to use it

Users can use the new functions hilbertEncode to convert coordinates into a Hilbert Curve value, and hilbertDecode to convert the Hilbert value back into coordinates. These functions can be called directly in SQL queries to encode or decode spatial data.