Shared types refactor

[austinabell]

Summary of changes
Changes introduced in this pull request:

• Moving shared types to own crate (was overloading the vm crate with things that shouldn't be for convenience)
  • If this crate gets bulky in the future we can just seperate by feature, but without it the crates won't be very composable and will cause a lot of issues
  • Moved gas tracker to interpreter crate (was placed in vm crate because it was shared, but now that all the components using it are in the same crate I moved there)
    (Issue arose from message crate having to pull in all proofs lib because of the conversions)

This refactor was pretty annoying, so hopefully we can agree on this (or something similar) so we don't have to revisit

Reference issue to close (if applicable)

Closes

Other information and links