Prototype Clickhouse and custom history module server support was added in DEV-4164, but the development was paused because there were plans to define one REST API for external history services and write proxies to different backends.

Sill having hardcoded clickhouse support would be useful, so the corresponding development is moved here:

• copy/update relevant DEV-4164 specification parts,
• copy/update history backend changes and server implementation,
• document Clickhouse API calls used by server and identify frontend requirements.