Store the module data in an arc to simplify a lot of things

[tertsdiepraam]

This PR does a couple of things:

1. The data of compiled functions is now freed when it is no longer being used.
2. Each TypedFunc now contains an Arc to that data to prevent it from being dropped too early.
3. This removes the lifetime parameter from TypedFunc.
4. Additionally, it allows us to get multiple functions from a single Roto file.
5. Finally, TypedFunc can now be cloned!

Yay for usability at the cost of some dirty code inside.