Hello!

What is the most idiomatic way to emulate the SQS MessageGroupId https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/using-messagegroupid-property.html in RQ?

The use case can be described like this:

• I have an unbound number of job groups (categories)
• Jobs that belong to a single group should be executed sequentially (to prevent race conditions)
• Jobs that belong to different groups may be paralellized