Add unsafe version of all the functions

[francois-baptiste]

BigQuery supports all its native functions to be safe (i.e. returning null) or unsafe (i.e. returning error) It would be nice to have the same support for here too.

This probably is valid for snowflake too but I don't use it so I am not sure.

https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#safe_prefix