fix: rename SHA function to SHA1 for DuckDB

[rustyconover]

Addresses issue #4185

[VaggelisD]

Let's add a test case for this, you can either add it to existing multi-dialect SHA tests (as in test_bigquery.py) or add something like this in test_duckdb.py:

        self.validate_all(
            "SHA1(x)",
           read={
              "": "SHA(x)",
            },
            write={
                "duckdb": "SHA1(x)",
                "": "SHA(x)",
            },
        )

[rustyconover]

@VaggelisD test added.