Add validation for configuration keys used in external dictionaries in ClickHouse.
Why it matters
This feature ensures that the configuration keys provided for external dictionaries are properly validated. It helps prevent misconfiguration and potential runtime errors by catching invalid keys early, improving the reliability and user experience when working with external dictionaries.How to use it
Users benefit from this feature automatically when defining external dictionaries in their configuration files. No additional action is required, as the system now performs validation of dictionary config keys during configuration parsing.