move the Sample class into the Rust implementation

[Llandy3d]

Currently pytheus-backend-rs has a OutSample class used to send the samples back to python, this was done because we couldn't duplicate the Sample class name as it was needed for both receiving samples & returning them.

With the new sample generation refactor the rust backend it's not using the Sample class at all. This means that it can be considered to actually move the implementation in there and get rid of the OutSample class altogether, this could open the consideration of moving the core pieces of the library in there as well.