infra: implement linters for pre-commit

[tt-rkim]

We want linters that

• Don't disturb our workflow too much
• Can run fixes automagically on changes/commits (probably through pre-commit infra)
• Can be installed as part of python_env/dev or pre-installed with ansible provision scripts

For the kinds of linters we may want now,

• black for Python
• isort for Python

For the kinds of linters that we may want but need to do a little more investigating,

• clang-tidy3.9
  • Seems like a good option with auto -fix command, but I read reports that it may be destructive/breaking to code. I may also be totally lying here and there is no magic -fix option, so if you know more than me about the C++ linting ecosystem (and you probably do), please comment
• flake8
  • May be destructive to workflow as there is no easy "autofix" option

For Python specifically, I believe we should hold off on static type checkers. They're a bit too much overhead right now, and it may be difficult to setup. Ex. Not all libraries have type stubs that are useful/correct

[tt-rkim]

I would appreciate any comments from you guys @abhullar-tt @DrJessop @coffeeandcheesecake @tt-nshanker

[tt-rkim]

Still need this. Leaving open