Add pre commit git hooks to automatically run autoformat script

[ZakyHermawan]

Description

Automatically run autopep8 in place, recursively each time you commit based on rules from autoformat_python.sh,
if there are some errors, your commit will get rejected (no commit) and your code will be modified in place,
just run git add and git commit again.
This pre-commit hook will only modify the .py files that you have changed.

Note: To skip commit hooks during a commit, you can use the --no-verify option with git commit.

How to use:

1. Install pre-commit package manager with pip install pre-commit
2. run pre-commit install to set up the git hook scripts
3. Make changes
4. git add
5. git commit
6. If your commit fails, simply run steps 4 and 5 again

Note: If you don't follow either step 1 or step 2, then the workflow will be same as usual (no git hooks will be run).

Why do we need this ?

One of the problems with GNU Radio codebase is that there is autoformat
script that is needed to run manually to pass format test in git action,
so I think it will be a good idea to add pre-commit git hook to handle the
formatting before commit.

Related Issue

Which blocks/areas does this affect?

Every .py files

Testing Done

Make a commit that violating our code convention in .py files, also make commit to modify non .py file

Change non .py file

Change .py file while violating code convention:

Checklist

• I have read the CONTRIBUTING document.
• I have squashed my commits to have one significant change per commit.
• I have signed my commits before making this PR
• My code follows the code style of this project. See GREP1.md.
• I have updated the documentation where necessary.
• I have added tests to cover my changes, and all previous tests pass.

[willcode]

I'm not going to be excited about anything that automatically changes code on my machine, even if it is useful.