Add farmFingerprint64 function for non-cryptographic string hashing

Why it matters

This feature provides users with a new hashing function that is faster than cryptographic hashes while producing a 64-bit fingerprint of strings, useful for applications like data deduplication, indexing, and quick comparisons where cryptographic security is not needed.

How to use it

Use the farmFingerprint64 function in SQL queries by passing a string column or literal as the argument, for example: SELECT farmFingerprint64(column_name) FROM table_name; to obtain the 64-bit hash fingerprint.