## Summary of the Pull Request
<kbd>win+shift+arrows</kbd> can be used to move windows to adjacent monitors. When that happens, we'll new re-calculate the size of the window for the new monitor.
## References
* megathread: #8888
## PR Checklist
* [x] Closes#10274
* [x] I work here
* [ ] Tests added/passed
* [n/a] Requires documentation to be updated
## Detailed Description of the Pull Request / Additional comments
In `WM_WINDOWPOSCHANGING`, the OS says "hey, I'm about to do {something} to your window. You cool with that?". We handle that message by:
1. checking if the window was _moved_ as a part of this message
2. getting the monitor that the window will be moved onto
3. If that monitor is different than the monitor the window is currently on, then
* calculate how big the quake window should be on that monitor
* tell the OS that's where we'd like to be.
## Validation Steps Performed
* <kbd>win+shift+arrows</kbd> works right now
* normal quake summoning still works right
a151607c79