bug(impala) A delimited table should be explicitly stored as textfile

[yi-you]

ibis/ibis/backends/impala/ddl.py

Line 67 in 88ffe33

class DelimitedFormat:

when the cluster's default format is set as parquet, this will cause an exception. It should be explicitly stored as textfile. such as

        if self.lineterminator is not None:
            yield f"LINES TERMINATED BY '{self.lineterminator}'"

        yield 'STORED AS TEXTFILE'
        yield f"LOCATION '{self.path}'"

[cpcloud]

@yi-you Thanks for the issue. Would you mind submitting a pull request for this? Looks like you've already done most of the work!