Add NFData instances
This MR adds an NFData
instance to MessageId
for the PGMQ broker, as that is required for the issue I'm working on (the Servant streaming client requires everything to be forced in NF).
As I was there, I have made some of the associated data types newtypes, as that's totally possible to do with associated data families and it's more efficient than using a data
declaration.
I can see there are CI failures, but I don't think are related to my MR.