Switch Connection' interpreter to map to StateT InterpreterContext IO
Switch Connection' interpreter to map to StateT InterpreterContext IO

The previous type of interpretConnProd was InterpretorContext -> Connection' r -> IO r,
but this didn't allow updates to the context to be passed to the next interpreter.
We changed the type to Connection' r -> StateT InterpreterContext IO r to allow
threading of the state ic to further calls.

clample/lamdabtc,clample/lambdabtc,clample/lamdabtc,clample/lambdabtc