Remove old singleton structure: PreferencesManagerFactory
Rework PreferenceDef
Extract TabPreferences into its own file
Extract PlatformPref into its own file
Extract Preferences into its own file
Extract WorkspacePreferences into its own file
Extract PreferencesDef into its own file
Extract PlatformPreferencesDef into its own file
Extract WorkspacePreferencesDef into its own file
Extract TabPreferencesDef into its own file
Remove old PlatformPref.js file
Fix some regressions