WIP Split composite key user control

Some refactoring

WinAppCommon/ViewModels/Items/ListMenuItemVm.cs

@@ -0,0 +1,30 @@
+using System;
+using Windows.UI.Xaml.Controls;
+using ModernKeePass.Domain.AOP;
+using ModernKeePass.Domain.Interfaces;
+
+namespace ModernKeePass.ViewModels.ListItems
+{
+    public class ListMenuItemVm : NotifyPropertyChangedBase, IIsEnabled, ISelectableModel
+    {
+        private bool _isSelected;
+
+        public string Title { get; set; }
+        
+        public string Group { get; set; } = "_";
+        public Type PageType { get; set; }
+        public Symbol SymbolIcon { get; set; }
+        public bool IsEnabled { get; set; } = true;
+
+        public bool IsSelected
+        {
+            get { return _isSelected; }
+            set { SetProperty(ref _isSelected, value); }
+        }
+
+        public override string ToString()
+        {
+            return Title;
+        }
+    }
+}