Identifiers formatting wip

[K-Phoen]

It's really easy to have inconsistent formatting for identifiers (type names, variables, classes, fields, ...)

This processing is split across various places: different jennies and templates mainly.

What about applying language-specific formatting conventions on the intermediate representations instead? It would guarantee a consistent output, and unclutter jennies+templates.

This PR experiments with this idea.

Would help with #235