Tag ClickHouse-related Sidekiq jobs

Let's tag all ClickHouse-related sidekiq job with the clickhouse tag using the tags metadata field.

This allows customers to move ClickHouse specific worker to a separate Sidekiq shard.

How:

1. Locate all Sidekiq jobs that are talking to ClickHouse.
2. Use the tags metadata field to add clickhouse.
3. Compile a new sidekiq queues YML file.
4. Update the ClickHouse documentation where we raise awareness about the tagging (plus announce it on slack).