OLED Dark Mode for Light Switch

### Description of the new feature / enhancement

For people with OLED displays, we often have to make tweaks (high contrast themes, color inversions, third party tools, etc.) to take full advantage of pitch-black dark mode. This feature would create an integrated OLED Dark Mode for Light Switch, utilizing total black (OLED pixel off) rather than the typical Windows dark grey. _**This could probably be easily achieved by allowing users to select Windows' built in Contrast Themes in Light Switch**_, although that wouldn't be the ideal implementation.

### Scenario when this would be used?

For people using Light Switch Dark Mode on OLED displays.

### Supporting information

[Contrast Themes](https://learn.microsoft.com/en-us/windows/apps/design/accessibility/high-contrast-themes)
[Some Folks Discussing OLED Dark Mode](https://www.reddit.com/r/OLED_Gaming/comments/1dnfc7g/true_dark_mode_in_windows_11/)

No implementation files, tests, or entry points are named. Start by locating the Light Switch utility and reviewing the linked Windows Contrast Themes guidance; define done as an integrated OLED mode that uses total black rather than the standard dark grey.

Written by the indexing model from the issue text.