Cache JSON schema information globally

[UpliftMacaw]

Right now, any time a user with query access to a Clickhouse datasource with a large JSON column opens a query editor, the plugin will always run this query SELECT arrayJoin(distinctJSONPathsAndTypes(data_json)) FROM "penguin"."raw_events";.

On large databases, this query can be prohibitively slow and memory-intensive. Ideally, this information shouldn't change that often and can be safely cached for a configurable time period.