Sink shouldn't read tables from all databases on start-up

[YaroShkvorets]

Noticed that the sink loads all tables from all schemas/databases on start-up, not just the specified database.
So in case of Clickhouse for example, if there is a table in an unrelated database with a valid schema that upstream library doesn't support, it throws an error:

{"severity":"ERROR","timestamp":"2025-03-25T16:14:59.243438056Z","logger":"sink-sql","message":"new db loader: load psql table: retrieving table and schema: clickhouse: unsupported column type \"AggregateFunction(argMin, Float64, Date)\"","logging.googleapis.com/labels":{},"serviceContext":{"service":"unknown"}}

[gowinder]

the same error

[max-chechel-vc]

same issue here