Rationalize python configuration on pyproject.toml and update build system to hatch

[butler54]

Issue description / feature objectives

The recommended method fro managing python packages now is using pyproject.toml which we already have (based on this: https://packaging.python.org/en/latest/).

setup.py is no longer a pseudo-requirement as you can put in different build systems. There are a large number of options fro build tools: https://packaging.python.org/en/latest/key_projects/. The python packing authority is supporting a number of them. hatch and hatchling is the most popular to the modernized tools.

Caveats / Assumptions

• The default new hatch project setup has a src directory. This will not be used.

Completion Criteria

• Build system is replaced with hatch
• As many as possible of the configuration files are converged on pyproject.toml