sql_gen.py: plpythonu_error_handler: Translate specific Python exception types to PostgreSQL error codes (ValueError -> data_exception) instead of assuming everything is a data_exception. When removing the PL/Python prefix, preserve the Python exception class in a DETAIL message. Support non-PL/Python internal_errors by re-raising them.
sql_gen.py: plpythonu_error_handler: Translate specific Python exception types to PostgreSQL error codes (ValueError -> data_exception) instead of assuming everything is a data_exception. When removing the PL/Python prefix, preserve the Python exception class in a DETAIL message. Support non-PL/Python internal_errors by re-raising them.