[OCaml] Post data sent in POST, not in GET

- But language and token parameters are sent in both GET and POST (just in case)
- So now go (and noop and any) take the lang parameter and the list of post paramaters
- The type RequestType is now Network and is with the other types in ApiTypes
- Unrelated, apiDump display the limit parameter (I forgot it when we changed the API about lists)