DeleteDB should call Close()

[wparad]

DeleteDB always gets blocked because the database is never closed. It should automatically be closed on Delete.

Otherwise something like this is necessary:

unwrap(await db).close();
await new Promise(resolve => setTimeout(resolve, 10000));

const deleteAsync = deleteDB(databaseName, {
    blocked(blockedVersion, blockedEvent) {
          logger.error({ title: 'Database blocked from being deleted', blockedVersion, blockedEvent });
    }
}