[fix] pfe-jump-links | when dropdown nav is closed in browsers that don't support scroll-behavior: smooth;

[Djfaucette]

Description of the issue

In browser's that partially or don't support scroll-behavior: smooth;, clicking a link on the mobile nav sends you to the wrong position in the DOM. This is caused by a race condition of the nav "closing" at the same time the browser is trying to choose where to scroll.

Impacted component(s)

Pfe-jump-links, perhaps pfe-accordion if we need to expose a new css property for devs.

Steps to reproduce

1. Go to any browser that doesn't support smooth scroll (I'm lookin' at you Safari)
2. Make sure your browser window is below 992px width
3. Open the mobile nav and click a link
4. Notice the final position of the scroll, and that the dropdown nav is closed
5. the browser scrolls to the correct position minus the height of the dropdown nav when expanded

Expected behavior

It should not take into account the height of the nav when expanded, and instead should resolve to the correct position as browsers who do respect smooth scrolling.

Screenshots

Related issues

[Djfaucette]

Hmm, wondering if we could perhaps expose the position: relative; rule on the pfe-accordion-panel when expanded. If we could change it to fixed while expanded inside pfe-jump-links then it would appear above DOM content and this would not be an issue.