Bug: Specifying a long stack name results in a failure of the underlying SAM application

[gargana]

This line causes the name to go over 80 characters which is invalid.

https://github.com/aws-samples/aws-marketplace-serverless-saas-integration/blob/master/template.yaml#L384

As per: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-sqs-queues.html#aws-sqs-queue-name we should allow CloudFormation to generate the name for us.