Enforce string literals delimited by quotes
For consistency, we should enforce the use of
" instead of
' unless the string has a
" when it should be allowed.
We could set up the "flake8" pre-commit hook https://gitlab.gnome.org/GNOME/pitivi/-/blob/master/.pre-commit-config.yaml to run flake8 such that is uses the https://github.com/zheller/flake8-quotes/ plugin to check the string literals.
Alternatively we could use https://github.com/edaniszewski/pylint-quotes but flake8 is preferred since it runs much faster.
The entire codebase should be run through the new hooks and fixed.