Make ClickHouse compilable and runnable on loongarch64
So far only basic functionality was tested (on real hw),
clickhouse server runs, exceptions works, client works,
simple tests works.
Added new type of authentication based on SSH keys. It works only for Native TCP protocol.
Co-authored-by: Nikita Mikhaylov <nikitamikhaylov@clickhouse.com>
Co-authored-by: Robert Schulze <robert@clickhouse.com>