[Feature Request] Persistent on close or "Smart" Application Window Sizing

### Problem

When VRCFaceTracking application launches, it always sizes itself to a default size without remembering its last known size.

On 1920x1080... this isn't much of an issue. However, for those who use 5120x1440 monitors... the VRCFaceTracking application window stretches very wide. I also tested with 2560x1440 and the window by default is a bit wide. All at 100% scaling.

### Solution

It would be ideal if the VRCFaceTracking application window was able to remember its resizing upon closing and relaunching. Or if there is some way to have default window sizes that were generally appropriate for various commonly used desktop resolutions, mostly affecting wider resolutions. Thank you.

### Examples (images below each resolution text)

**1920x1080@100% scale** - not terrible

**2560x1440@100% scale** - window is a bit stretched, not terrible

**5120x1440@100% scale** - window is very stretched horizontally

No files or tests are named in the issue. Start by locating the C# desktop application's window initialization and startup/close handling; done means the window restores its previous size on relaunch or applies an appropriate default, with behavior checked at the cited resolutions.

Written by the indexing model from the issue text.