`quick-mention` should be disabled on hidden comments #4603

What I don't like

<img width="201" alt="Screen Shot 3" src="https://user-images.githubusercontent.com/1402241/126857642-17b2eac6-1dab-4772-a8dc-055b0b4733b1.png">

URL: https://github.com/sindresorhus/refined-github/issues/3686#ref-issue-864796824

It's ok if we only avoid adding the button on first page load