Setting page UI enhancements

### Description of the new feature

The first of my two requests it simple. I'd like to see the tab when on the Settings page match the settings page appearance. As you can see in pictures I attached, the Settings tab is black, but the Settings Page itself is a dark gray. I think they should match.

Additionally, it would be super nice to allow for enabling acrylic mode for the Settings page (and tab) itself so that it would be possible to match my current settings for terminal windows.

### Proposed technical implementation details

_No response_

Start by locating the Settings page and its tab in the Windows Terminal UI, then compare their current colors and how terminal acrylic settings are applied. Define the scope for matching the tab and page appearance and enabling acrylic on both; done means the visuals match and the setting works consistently.

Written by the indexing model from the issue text.