Optimize random map/song select and cursor movement

[erenggteam]

For me on an i3-1115G4 CPU, picking a random song always lags for 0.5-1s and I see in RTSS that it is way too much CPU intensive, for a feature that just randomly selects a song from a list. And the cursor while playing a map always tends to freeze for, again, 0.5-1s and teleport to where it should be, which I also notice is very CPU intensive, for simple cursor tracking(and some telemetry of course). I know I dont have the top of the top CPUs, but this shouldnt be that hard to run on osu!lazer of all games. I'd like at least a concise explanation on why its so hard on the CPU if doing further optimization is practically impossible.

[pigeonskew]

Have you tried using other renderers? They might help.

[peppy]

Random performance

How many beatmaps do you have loaded? This will likely improve with the upcoming rewrite of song select if you have many beatmaps loaded

Input stutters

Probably ppy/osu-framework#6235, ie. windows-is-single-threaded-mostly and some other app on your system is causing the input handling to get delayed. Not our fault but we can improve by handling input a different way.