refactor!: Converts Project into a Python Compatible Package

- Moves all core functionality files to the package "openvoice";
- Adjusts all inner package references to the new format;
- Adds "setup.py" file following the specification present on "https://packaging.python.org/en/latest/guides/distributing-packages-using-setuptools";

BREAKING CHANGE: All the core functionality files were moved to the "openvoice" package