Fix three issues with display of answers on the problem grader page.

[drgrice1]

First, if an answer is a checkbox answer with multiple parts checked, then the ⍮ character is not handled. This needs the same processing as is done on the past answers page for this.

Second, the essay answers can not be put into a Mojo::Collection and joined with <br> tags. The result of that is a Mojo::ByteStream which means that it is not escaped. That was the original point since the <br> tags cannot be escaped. However, the answers must be escaped so that answers like <script>alert('xss attack')</script> are not executed. So a for loop similar to that used for the checkbox answers must be used. Note that these answers were also wrapped in a redundant <div> tag with the same class as the containing <div> that is still there, and that was removed.

Third, there was a dangling end </div> tag for formula answers that was removed.

[Alex-Jordan]

Is the backslash after the ⍮ meant to be here?

[drgrice1]

Yes, the backslash is intended. That prevents a newline from being injected, and thus creating a white space node in the HTML output. Here are screenshots showing the difference (the first image is with the backslash, and the second without):

and here is the difference in the generated HTML (again first with the backslash, and second without):

								<td style="color:#006600" class="px-3 ">
C&#9070;D&#9070;E&#9070;F								</td>

								<td style="color:#006600" class="px-3 ">
C&#9070;
D&#9070;
E&#9070;
F								</td>