Basic FFB support for steering wheels

[Arkhist]

In this pull request I provide a basic implementation of FFB for steering wheels on SDL3.

In FFB territory:

• Constant effects are supported
• Damping effects are supported (this could be vastly improved, I do not master how this effect works)
• Autocentering and gain is supported

I added two settings:

• FFBGlobalGain: controls the total gain of the haptic device
• FFBAutocenterGain: is multiplied with the autocenter strength (on my wheel, autocentering is really really strong compared to every other effect, justifying this effect for me).
• FFBRumbleGain: is multiplied with the rumble strength (to me, rumbling was way too strong compared to other effects and I needed to tune it down)