Mouse/trackpad options

### Feature Description

I'd like to see a "Mouse & Trackpad" tab in the Settings app to be able to configure mouse & trackpad options like sensitivity, acceleration speed & profiles (custom profiles would be even cooler, but I assume many compositors do not implement this libinput feature), natural scrolling for trackpads, etc...

### Use Case

Having a universal GUI instead of having to modify settings in the compositor's configuration file would arguably be pretty nice, in my opinion.

### Compositor(s)

All compositors

### If Other, please specify

_No response_

### Proposed Solution

I don't think it would be very different to other settings modifying the compositor's configuration file. However, I do wonder if DMS has a way to access libinput configuration, or if that's locked to the compositor. I'm asking this because a feature I'd like to see implemented is, as I've already said, custom acceleration profiles, but this supposedly depends on the compositor to implement? If it doesn't, perhaps DMS could also directly modify libinput settings as well?

### Alternatives/Existing Solutions

_No response_

The issue names no files, tests, or entry points. Start by reviewing the existing Settings app and compositor-configuration paths, then determine how libinput options can be accessed across the listed compositors; done means a documented, supported Mouse & Trackpad tab with the agreed options working consistently.

Written by the indexing model from the issue text.