Zome API function name formatting / casing

[pospi]

It would be nice to have more flexibility in the way JSONRPC function names are exposed to the outside world. Primarily because Holochain uses snake_case parameter and function names, and the reference API for our app uses lowerCamelCase. So, any of our client-side code that deals with multi-word parameter names needs to do this kind of translation.

I would advocate support for something similar to the #[serde(rename_all = "camelCase")] attribute which can be optionally added after the #[zome_fn(...)] macros to control this behaviour.