Revert overflow-x: auto on .problem-content divs.

[drgrice1]

This was added in #1432, but is causing problems. If an answer rule is contained in a position: relative parent, then the MathQuill toolbar ends up being positioned correctly, but is contained inside the .problem-content div, and so you need to scroll to the right to see it. Note that the .ww-feedback-container is position: relative. So any answer inside a div with that class will have this issue.

An example problem for which the problem occurs is:

DOCUMENT();

loadMacros('PGstandard.pl', 'PGML.pl', 'parserMultiAnswer.pl', 'PGcourse.pl');

$ma = MultiAnswer(1, 2)->with(singleResult => 1);

BEGIN_PGML
[<
    Enter 1: [_]{$ma}{5}

    Enter 2: [_]{$ma}{5}
>]{ [ class => 'ww-feedback-container ww-fb-align-middle' ] }
END_PGML

ENDDOCUMENT();

Note that this is not a problem when using the problem editor, since the width of the .problem-content div is the same as its parent. So this will need to be tested in an actual set.

For now the overflow is left for solutions and hints. Those won't have answer rules, and thus will also not have the MathQuill toolbar issue.

So a different way to fix the issue with dark text overflowing into the dark region outside of the problem will need to be found. Any ideas?

[Alex-Jordan]

I saw the issue with the posted example and I see that this fixes that issue.

As for dark mode, it seems to me that we would just need to actually render the problem for dark mode. So its text (including math) would be white. And the problem background would be dark. I guess this would raise issues with image files that were never considered for dark mode use though.