Packaging: Use of pyproject.toml and move to minimal setup.py for modernization

[fmalatino]

Description
This PR moves the metadata and configuration for the package to a pyproject.toml file, as is prescribed by Deprecate legacy setup.py develop mechanism for pip install --editable #11457. The previous setup.py file is now minimal.

Fixes # (118)
This PR also addresses Issue 118

How Has This Been Tested?
Tested using the current CI suite.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules
• New check tests, if applicable, are included

[FlorianDeconinck]

So the issue with that is we can't control for release anymore. When you pull the package you get develop, which is risky but ok if you are on the develop branch of Pace (you agree to be on the "expected stable" branch, with the caveat).

But when you release Pace you want hard encoded versions. Is the plan to change those path to a release tag when making a release with Pace?

[fmalatino]

Definitely need a broader discussion on this, but I think moving forward we will have release branches that will point to the most recent release for each dependency, while the develop branch will point to the develop branches. I will be pushing a minor change shortly that will amend the current CI.

[FlorianDeconinck]

Not a bad strategy, it would made the "release" commit pretty clear and allow "released" codebase to also be moved onto develop or other branch after the fact, which is a nice perk.

There's probably something out there that automatize this process, though it's simple enough it can be documented up (so you and I aren't the only ones knowing how to release!).

[oelbert]

nice nice

[oelbert]

lgtm