Make a prefs zustand store

[OhKai]

The prefs are currently not reactive (just read on render). When a component makes a pref change (e.g. the sidepanel in the processes view) other components relying on that pref don't know about it. This lead to some extra code, just to trigger a rerender in the icon list view when the pref changes.

Instead, we should implement prefs in a zustand store so that it can be shared across components and changes are reactive on all dependent components.