color-contrast can return needs review when text is multiline and has `white-space: pre-wrap`

Similar to https://github.com/dequelabs/axe-core/issues/5127, however this is caused by having `white-space: pre-wrap` on the span. This causes the text to have a 3rd text rect that is just whitespace at the end of the line (4px wide). The main problem is that this whitespace rect is outside the normal bounding rect of the element and so can easily have a different background stack than the other rects.

In the following example, the text is fully within the first column and shouldn't produce different background rects, however the `pre-wrap` causes a whitespace rect to appear outside the bounding rect of the span and then be positioned on top of the 2nd `.column`, resulting in a different background stack (and the same `elmPartiallyObscuring` message). If you remove the `pre-wrap` color contrast passes without issues.

```html

main {
position: relative;
display: flex;
}
.column {
width: 390px;
height: 900px;
border: 1px solid;
}
.footer {
position: absolute;
width: 392px;
background: black;
color: white;
}

```