Add GHA workflow to lint Python files

[kenorb]

We need to add GitHub workflow to check for valid Python syntax.

File: .github/workflows/lint.yml Branch: dev

• We can use flake8, see: https://help.github.com/en/actions/language-and-framework-guides/using-python-with-github-actions
• Or this one: https://github.com/WhyNotHugo/python-linting
• Or this one: https://github.com/marketplace/actions/python-lint

[kenorb]

Related: https://github.com/EA31337/FX-Data-Convert-Action/commit/664116d313e8191be08887a592e4aa3881bad031