Fix packaging to install only the choreographer module

[hirohira9119]

Closes #266

As discussed in #266 the current configuration causes tests and results folders to be installed alongside the package.
This PR updates pyproject.toml to explicitly install only the choreographer package, preventing unintended directories (tests, results) from being included in the distribution.

[ayjayt]

So same effect, I changed strategy:

1. I chose not to use packages= because by specification you're supposedly to list all sub-packages (even tho our build system doesn't require it, it complained).
2. I turned off namespaces
3. I moved to a src directory
4. I made the resources/ data folder a python subpackage by including __init__.py

Runnig uv build --wheel will show the output- remember to clear your build/ as, unfortunately, setuptools doesn't do that for you.