Feature Request: Store HyperDX metadata in ClickHouse.

[itkillsnone]

MongoDB is currently used as metadata storage for HyperDX for user authentication, data source storage etc. However using MongoDB in a multi-tenant manner can be tricky because we have to make sure one tenant cannot read another tenant's data. Besides, using MongoDB make the system a little more unstable because there is one more dependency in the system.

So we are thinking maybe store the metadata directly in user's ClickHouse instance, maybe create a default database for HyperDX in ClickHouse like 'hyperdx_metadata'.