[refactor] combine checkInputs/Outputs and use for(M)

[acl-cqc]

There were two goals here:

• combine the common parts of checkInputs/Outputs, that is, they are the same apart from flipping of Src/Tgt (with Bool flag to checkWire) and the error message
• Get a list of Src+Tgt pairs, and forM over them - this should make it nice and easy to use Fork in Multi-threaded type inference #41

Felt I jumped through a few hoops to preserve behaviour, but maybe that's worth it, specifically I liked doing the do-the-wires-match-types before the "is there anything leftover" check.

Individual commits should all compile if you want to look at some intermediates (these may be plausible endpoints)

[acl-cqc]

Of course if we got rid of the extensive existing type signatures for checkInputs and checkOutputs then the line count here would look much better ;-). (Each of checkInputs and checkOutputs is used twice though so I don't think inlining is a good idea)

[acl-cqc]

Type signature here is

 [(NamedPort exp, BinderType m)]
 -> [(NamedPort act, BinderType m)]
 -> ([(NonEmpty (NamedPort exp, BinderType m), NonEmpty (NamedPort act, BinderType m))]
    , Either Error [(NamedPort exp, BinderType m)]
    )

if you really want it (!)...perhaps with a type TypedPort e m = (NamedPort e, BinderType m) ??

[acl-cqc]

This might be better called zipSuffixes or zipWithSuffixes, though