#1: Create Python package / Repository refactor

• Get rid of broken M$ GH mirroring
• Update package.json
• GPL-3.0-or-later licensing
• Rename the repository, package name, and folder to g1_monetary_license (Repository will be renamed once this MR is approved)
• Add pyproject.toml for Python packaging
• Add PyPI and PyPI test publication jobs
• Introduce release script
• Add CONTRIBUTING.md: document how to update the version
• Rework README.md
• Proofread fr/en
• Do not translate rST metadata
• Introduce CHANGELOG.md
• v0.3 release (commit and tag will be added to the MR once approved)