Add BITAND_AGG, BITOR_AGG functions (enabled in Snowflake library)

Snowflake supports the BITAND_AGG and BITOR_AGG functions, these are identical to the BITAND and BITOR functions supported by the standard.

BITAND_AGG docs and examples: https://docs.snowflake.com/en/sql-reference/functions/bitand_agg
BITOR_AGG docs and examples: https://docs.snowflake.com/en/sql-reference/functions/bitor_agg