[Release] Setup wheel and release scripts

[comaniac]

Description

• Setup scripts for building wheels and uploading to PYPI.
• Change the versioning approach. Now we follow Alpa and Ray to use PEP-440 convention.
• Add a Github Action workflow to automatically build and upload the latest wheel to PYPI when we make a new release in the repo. There's no way to test this workflow right now, so we need to keep an eye on the next release.
• When packing, I found that some folders don't have __init__.py so that will be ignored by sdist and pylint.
• Accordingly, this PR also fixes some more lint errors that we missed previously.

The first release v0.0.1 cut at the current main branch has been uploaded to PYPI. We will keep using v0.0 series for now. When everything is ready, including unit tests, documents, etc, we will release v0.1, which should be the first official public release of Slapo.

Checklist

• PR's title starts with a category (e.g. [Bugfix], [Model], [Tutorial], etc)
• Changes are complete (i.e. I finished coding on this PR)
• All changes have test coverage
• Code is well-documented

cc @chhzh123

[chhzh123]

LGTM. Thanks @comaniac for setting up the wheel.