Unable to change clickhouse log level

[roxannelandry]

Proposed change

Add a log level options for clickhouse in values.yaml

Additional context

Normaly when deploying clickhouse docker there's a param in the config to be able to change log level. Currently debug level is hardcoded in the posthog chart so we can not change that. In GCP it is causing extra cost because of log storage. It would be nice if we could tel in the values.yaml the clickhouse log level we want (trace, debug, information, warning, error)