Add Native Mouse Support for Right Stick (Camera Control)

[gamersalpha]

Your suggestion

Hi! I'd like to suggest a lightweight quality-of-life improvement:
Allow users to bind mouse movement (X/Y) directly to the right stick in Input Settings.

This would mainly be used for smooth camera control in games like Breath of the Wild when using keyboard and mouse. Right now, the only way to do this is via third-party tools like Mouse2Joystick, which require extra drivers and are no longer maintained.

This isn’t a major feature or a big system change — just a small input option that would make Cemu more user-friendly for PC players without controllers. If basic sensitivity or deadzone controls can be added, even better — but not essential.

Thanks for considering it, and for all your awesome work on Cemu!

[cabrerahector]

Duplicate of #256.