Update pyfaust wrapper (details below).

- Fix any Faust member function that creates an intermediate Faust to interact with the current Faust but not passing the dev argument to ensure that the enw Faust is on the same device (cpu or gpu) as the current Faust (for example in concatenate).
- Unify Faust.clone and manage all kind of conversions in the C++ core (instead of gathering the factors manually in python the create another Faust).
- Add the missing support of swap_cols and swap_rows for GPU Faust.