Support random value generation in target languages

* Start with e.g. `Direction2d.random()` directly returning a randomly-generated value, using Haskell's built-in stateful global generator
* Maybe eventually add support for generator objects with seeds and stepping?

Start by locating Direction2d and the Haskell implementation of its random-generation entry point. Scope the initial work around Direction2d.random() using Haskell's built-in stateful global generator; generator objects with seeds and stepping are only a possible later extension. Done means the initial random-value API is implemented for the requested target languages and its behavior is verified by the relevant project checks.

Written by the indexing model from the issue text.