Default Screen / Monitor Option to open apps on

### Description of the new feature / enhancement

It would be useful if there was an option that could be toggled to force app to open on a particular screen.

### Scenario when this would be used?

I share my screen a lot during Teams meetings as I deliver training online. The nature of what I deliver means switching between apps regularly (PowerPoint, word, web browser, Visual Studio, VSCode to name a few) so sharing a second screen is the most effective way to do this. When I am delivering training I would like all apps to open on my primary monitor so I can always control what is being shared.

### Supporting information

_No response_

The issue names no PowerToys utility, file, entry point, or test. First identify which utility owns app-window placement and review how Windows monitor selection is currently handled; done should include a toggle that consistently opens apps on the chosen monitor.

Written by the indexing model from the issue text.