added Serialize instance for EndPointAddress

[robstewart57]

Adds a Serialize instance for EndPointAddress. This adds binary serialization support using the cereal package, on top of the existing support for the binary package with the Binary instance.

@edsko , could you take a look at this when you get a chance? There might be a good reason that this is not currently in Network.Transport that I am not aware of?

[hyperthunk]

I'm happy to merge this if @edsko agrees it's okay to take the extra dependency. @edsko @dcoutts thoughts?

[edsko]

This is one for @dcoutts I think -- he tends to care more about dependencies :)

[dcoutts]

If we can avoid it, I'd rather not. As far as I know, there are now no good reasons to pick cereal over binary. The binary package now does the incremental data input stuff (and it's now faster than cereal). The binary package is the one on track to be added to the platform. If there's anything left, then we should just fix binary, the binary authors are keen.

Presumably as a workaround one can just make an orphan instance, since the EndPointAddress constructor is exposed.

[robstewart57]

Thanks Duncan for addressing this ticket. In fact, HdpH adopted the cereal package, and hasn't been considered since that we move to binary. I'll just add an orphan instance for EndPointAddress for cereal within the HdpH codebase.