Inactive message scenarios for assignment and capacity rules

There should be a way that as a company you can decide how to assign inactive message conversations. 

For now, they don't affect capacity, but for some organisations, the message ticket is the same as an email ticket so it could have a specific workload. 

Maybe what some customers need it to have the option on:

- how inactive message are assigned to the first agent > all at once or round robin model within the team

- how inactive messages affect capacity > based on inactive/active status or based on ticket status (open vs not open)