[EM-815] Update Settings GUI component positions

[BlackBeltPanda]

• Updates the positions of the components in the Settings GUI
• Corrects the scroll gradient color
• Updates the back button icon image

Fixes EM-815 (https://linear.app/sparkuniverse/issue/EM-815)

[Sk1er]

Neither scrollbar works on this PR because both of them are parented to dividers that are outside of their parent component's bounds

[BlackBeltPanda]

Superseded by EM-1771