[Slider] Modernize implementation

[mj12albert]

1. Replaced useCompound with Composite

Previously the id attribute of all the input elements were passed to useCompound as metadata to generate the for attribute of the output element.

However the refs provided by Composite can't be used during the render of Output for this, so the ids have to be held in a new state

2. Converted types to namespaces
3. Fix https://github.com/mui/base-ui/issues/635
4. Hooks/context are no longer exported for now - it's no longer possible to (easily) implement a Material Design slider as it would require custom subcomponents

• [x] I have followed (at least) the PR section of the contributing guide.