From Pipenv to PDM

[SharonHart]

Change Description

• Drop pipenv for PDM
• Implement DRY by instructing PDM to take dependencies from the new pyproject.toml, dropping the Pipfiles.
• That change required moving server dependencies to the pyproject.toml, as 'server' optional dependencies. Same goes for dev dependencies.

Checklist

• [x] I have reviewed the contribution guidelines
• [x] I have signed the CLA (if required)
• [x] My code includes unit tests
• [x] All unit tests and lint checks pass locally
• [x] My PR contains documentation updates / additions if required