Check in pypi the latest specification for pyproject.toml

[dgarijo]

Based on https://github.com/oeg-upm/codemeta/blob/crosswalks_oeg/crosswalks-sssom/PyPa/pypa-codemeta-mappings.yml
and on https://packaging.python.org/en/latest/specifications/pyproject-toml/ we have to revise how authors are declared, and how licenses and project urls are detected. We need tests for:

• single author + email + org
• multiple authors (separated by commas or not)
• etc.

[dgarijo]

This is not to update our own pyproject, but to test how the distutils specification works

[dgarijo]

@Anas-Elhounsri this is relevant to your contributions