Add missing `Hash` output format to `ClickHouseFormat` enum (JDBC/DataGrip throws "No enum constant ... Hash")

[allegrinisante]

Use case

Running a SELECT ... FORMAT Hash query through the JDBC driver (e.g. from DataGrip) fails with:

No enum constant com.clickhouse.data.ClickHouseFormat.Hash

The Hash output format (https://clickhouse.com/docs/interfaces/formats/Hash) is supported by the ClickHouse server but is not present in theClickHouseFormat enum, so the driver throws before the query is ever sent.

[chernser]

Note: this problem primarily in handling unknown format by old clients. Code is using enum ClickHouseFormat that is used to avoid comparing with string and have some checks. But when client have to convert string to enum it will fail. In case of Client used directly with Stream of the data it is not very convenient because requires to wait for library update. Instead we could use Unknown constant as a fallback.