Migrate Python Packaging to pyproject.toml

[SharonHart]

Change Description

Modernize packaging by migrating from setup.py to pyproject.toml:

• Dropped all setup.py and setup.cfg
• Added pyproject.toml for all 5 presidio packages
• Used 'flat-layout' automatic package discovery, dropping all tool.setuptools and tool.setuptools.packages.find options
• Read versions from VERSION file, add one where missing
• Used bdist wheel pakaging, updated release pipeline accordingly.

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