Major OpenDatabaseUserControl refactor, now has proper ViewModel

Status text and password box border colors are updated according to database status
Update composite key in Settings work
Some code cleanup

ModernKeePass/ViewModels/SettingsVm.cs

@@ -0,0 +1,46 @@
+using System.Collections.ObjectModel;
+using System.Linq;
+using Windows.UI.Xaml.Controls;
+using ModernKeePass.Common;
+using ModernKeePass.Interfaces;
+using ModernKeePass.Pages;
+
+namespace ModernKeePass.ViewModels
+{
+    public class SettingsVM : NotifyPropertyChangedBase, IHasSelectableObject
+    {
+        private ListMenuItemVm _selectedItem;
+
+        public ObservableCollection<ListMenuItemVm> MenuItems { get; set; }
+        public ISelectableModel SelectedItem
+        {
+            get { return _selectedItem; }
+            set
+            {
+                if (_selectedItem == value) return;
+                if (_selectedItem != null)
+                {
+                    _selectedItem.IsSelected = false;
+                }
+
+                SetProperty(ref _selectedItem, (ListMenuItemVm)value);
+
+                if (_selectedItem != null)
+                {
+                    _selectedItem.IsSelected = true;
+                }
+            }
+        }
+
+        public SettingsVM()
+        {
+            MenuItems = new ObservableCollection<ListMenuItemVm>
+            {
+                new ListMenuItemVm { Title = "Database", SymbolIcon = Symbol.Setting, PageType = typeof(SettingsDatabasePage), IsSelected = true },
+                new ListMenuItemVm { Title = "Security", SymbolIcon = Symbol.Permissions, PageType = typeof(SettingsSecurityPage) },
+                //new ListMenuItemVm { Title = "General", SymbolIcon = Symbol.Edit, PageType = typeof(SettingsGeneralPage) }
+            };
+            SelectedItem = MenuItems.FirstOrDefault(m => m.IsSelected);
+        }
+    }
+}