Fix RetroBat/RetroArch Emulator Scaling on Ultrawide Monitor

RetroBat is a Windows-specific solution for running EmulationStation and RetroArch, along with other emulation software. I normally run it on a PC connected to my main TV where I can also run Steam in Big Picture Mode for more modern games. However I recently set up RetroBat on my gaming desktop, which has a 21:9…