Synchronizes the given repository's table with data fetched using a specified query.

The synchronization is done via a single SQL query by utilizing the WITH statement. It first executes INSERT .. ON CONFLICT (called "upserting") to insert and update new rows, followed by DELETE .. WHERE that removes old entries that didn't appear in the input query.

Returns a tuple with a number of upserts (inserts + updates) and a number of deletions.