Now that we have an interface for fortran, python, javascript, soon to be julia with #639, we should make it easy to find the code for each language. Rename the musica folder to python

Acceptance criteria

• musica folder renamed to python
• pyproject.toml updated to look in python for the python code
• CI tests updated to run tests for python out of the python folder if needed
• Paths in python tests updated to use the new folder path

Ideas