[J4] Removes fixed max-height on sidebar-nav on wide screen

[regularlabs]

In PR #31092 a fixed height was introduced to the sidebar-nav to fix things on mobile screens (smaller than md).
But this causes a useless scrollbar and height limit on the sidebar nav on wider screens.

So this PR removes it.

Check the styling of the sidebar in the global configuration before and after this PR.

Before:

After:

[regularlabs]

Also fixes this issue: #31928

[brianteeman]

(it wasn't just for mobile screens @ceford do you want to explain what the problem was you were solving)

[ceford]

31092 had nothing to do with mobile screens or screen width in general. It was about height. The list of Help screens in particular is very long - you had to scroll down a long way for the later ones, and when clicked on nothing appeared to happen because the help screen is loaded into a frame out of site at the top. Frankly, the Options list works better this way too. So I object to this PR. It is a step backwards and does not seem to solve any particular problem. The scrollbar is not useless! The lack of indication that there are more items further down is a more general problem that needs its own solution.

[regularlabs]

Well, I think it is very weird to have the sidenav as an extra scrollable section. It would only make sense if that part was fixed to the same height of the browser window. But now, on many screen sizes, you have to scroll the main window down to see the bottom of that nav section... and then scroll that section down even more.

In my opinion the 'fix' applied in #31092 is a crude way to solve something that causes more issues and frustration than it is worth.

Anyway... my 2 cents. Do with it what you want...

[regularlabs]

PRs that cause discussions are not worth my time. So closing this.