Fix inconsistent line length and move configs to pyproject.toml

[browniebroke]

Description

• All our linters require different line length: line them all up at 119.
• Move all supported configs to pyproject.toml with notable exceptions being (AFAIK) flake8 and pycodestyle
• Move pytest & coverage configs to pyproject.toml

This max line length number was suggested to be aligned with Django's itself, but since then, they adopted black and moved to 88. I'm sticking to the initial suggestion of 119 for this pull request, we can see how some lines are no longer wrapping and IMO read better.

Checklist:

• I've made sure that tests are updated accordingly (especially if adding or updating a template option)
• I've updated the documentation or confirm that my change doesn't require any updates

Rationale

Fix #2720 see issue for rationale.
Fix #4170

Closes #4270