Code sniffer code style fixes

I'm planning to incorporate this ticket into 📌 Adopt GitLab CI template Needs review so we can fix all those things in one single merge request.

Updating issue credits.

Latest test run highlights some more fixes which are needed. Will fix them on the parent.
https://git.drupalcode.org/project/poll/-/jobs/715342

PHPCS fixes resolved: https://git.drupalcode.org/project/poll/-/jobs/715890

Automatically closed - issue fixed for 2 weeks with no activity.