Remove line length limitations and use the same flake8 and isort config as bugbug

[marco-c]

We can copy the code style configuration from https://github.com/mozilla/bugbug.

[adahanu074]

@marco-c, can you please assign it to me?

[marco-c]

@adahanu074 we don't assign issues, you can work on them as long as there is no PR attached to it :)