Include screenshots in compatibility reports

[unknownbrackets]

The main high level things this does:

• Adds a way to cap screenshot dimensions at high resolutions, no UI.
• Allows optional screenshots (max 1920x1088) and icon upload to the server.
• Enables mipmaps for savestate screenshots in more places.
• Shows the Feedback button even when reporting is disabled, and prompts to enable.

The reason reporting is required is that reports (especially negative ones) without error information aren't very useful. We could disconnect it, with some changes.

Note: currently the server is storing but not serving these images. For security reasons, we'll need to validate the uploaded images before serving, but at least they aren't going into a blackhole

-[Unknown]

[unknownbrackets]

Whoops, looks like I generated an ICE on some gcc versions. I'll just remove, wanted to be explicit that it was zeroed...

-[Unknown]