Adding 16:9 Aspect Ratio

[callowaysutton]

Someone already made a mod with this feature and I was wondering if you could make a drop-down menu button for the stage (whether you want it as 5:4 or 16:9). This would allow more of a modern game designing experience since you almost never have to design graphics for a 5:4 ratio (Newer games at least).
If you could implement this, that would be awesome!

[ckissane]

I think instead, we could add a dynamic ratio that is not only one of two options.

[NoMod-Programming]

@coler706 @Wettining @GRA0007 How about a dialog with some preset options, and an option for a custom resolution? Also, a 16:9 Aspect Ratio does not denote screen resolution, so what would be the resolutions for this? We can't assume everyone is at 1080p or at 4k or at 8k, so we need to find something that would work, look nice, and be useable.