Clickhouse: Add readiness check to eventually replace feature flags
What does this MR do and why?
Instead of ClickHouse being controlled with a feature flag, add a settings switch that can be used along with a check to ensure everything is configured properly.
This MR adds a boolean configured?
method that returns true when all expected ClickHouse databases are available (currently main). A follow-up MR will add a boolean setting that replaces the feature flags.
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Related to #428585 (closed)
Edited by Adam Hegyi