Feature Request: Show GPU Performance mode

[ItzSelenux]

I know and already have "exec=echo -n "$(</sys/class/drm/card0/device/power_dpm_force_performance_level) performance" in my MangoHud configuration. However, when playing games with Proton, I can't see the performance level. I think it's useful to know and care about the performance level because:

In lightweight games, switching to low-performance mode can help lower temperatures.
If a game runs with a low framerate, checking if the performance is not set to low performance mode could be beneficial.