improve meep code quality

[joamatab]

Improve quality code:

• [x] add pre-commit hooks for keeping the quality up and apply black format (#2164)
• [ ] add type annotations
• [ ] fix mypy issues
• [ ] fix flake8 for syntax errors flake8 python --count gives 1193 errors
• [x] simplify code (#2164)
  • Replace if statement with if expression (assign-if-exp)
  • Convert for loop into list comprehension (list-comprehension)
  • use fstrings

Keep up quality code

• [x] add CI/CD for code checks
• [ ] mypy type checker
• [ ] flake8 for syntax check (see #2177)
• [ ] improve error messages
• [ ] speed up CI/CD

[joamatab]

may require rebasing existing PRs

662

[ianwilliamson]

meep.adjoint.* had the yapf formatter applied to it, but I am not sure if subsequent PRs kept this up. See https://github.com/NanoComp/meep/pull/1590#issue-910874343

[joamatab]

We applied black to python code and clang to the c++

Now it runs with pre-commit hook