Function duckdb_appender_end_row 

pub unsafe extern "C" fn duckdb_appender_end_row(
    appender: duckdb_appender,
) -> duckdb_state

Finish the current row of appends. After end_row is called, the next row can be appended.

@param appender The appender. @return DuckDBSuccess on success or DuckDBError on failure.