Wait for paused database to launch

[iiLaurens]

If you send a query over rds-data using boto3 on a paused Aurora Serverless database, an error will be returned:

BadRequestException: An error occurred (BadRequestException) when calling the ExecuteStatement operation: Communications link failure

It only takes a few seconds for the database to launch after this first failed query response. So it would be a nice feature if this package intercepts the Communications link failure and retries every second. You can simply probe the status by sending a dummy SQL statement, for example SELECT 1 would already suffice. This user on stackoverflow proposed a similar solution.

Would it be possible to include this functionality in the package?

[kislyuk]

This would be a great addition (as long as there is a timeout so the call doesn't wait forever). Would you like to open a PR?