Update Scale Result image aspect ratio

Description: **VALUE STATEMENT:**
When an assessment author builds an assessment, they may choose an optional image to show as part of the result. As a user, I should be able to see the author’s image in the correct aspect ratio.

**ACCEPTANCE CRITERIA:**
– Scale result
– The author is forced to crop the image to 1488 x 454 and so the user should see the image in that exact aspect ratio
Owner: