Prototyping serialization without typeclasses in the haskell backend

[timbod7]

So far I've just hand translated the

https://github.com/timbod7/adl/blob/master/haskell/compiler/tests/demo1/input/picture.adl

and added some support to the adl runtime.

[timbod7]

The basic pattern is that functions that previously had signatures like:

fn :: AdlValue a => ....

now become

fn :: JsonBinding a -> ...