Improve userpref

This PR improves the user prefs

• Reduce store update with a debounce of 500ms
• Reduce re-entrant events with the use of timestamps per user preferences
• Use string-like path for user pref names, instead of string[] (reduce verbosity, and use basic object for the key)

Previously the React dependencies was also not properly catched. The provided user preference setter was always overridden. This PR also fixes this problem.