Moved application code to the Application layer

Imported Win10 project
Code cleanup
WIP - Use common UWP services for Win8.1 and Win10

ModernKeePass10/Actions/ClipboardAction.cs

@@ -0,0 +1,27 @@
+using Windows.ApplicationModel.DataTransfer;
+using Windows.UI.Xaml;
+using Microsoft.Xaml.Interactivity;
+
+namespace ModernKeePass.Actions
+{
+    public class ClipboardAction : DependencyObject, IAction
+    {
+        public string Text
+        {
+            get => (string)GetValue(TextProperty);
+            set => SetValue(TextProperty, value);
+        }
+
+        public static readonly DependencyProperty TextProperty =
+            DependencyProperty.Register("Text", typeof(string), typeof(ClipboardAction), new PropertyMetadata(string.Empty));
+
+        public object Execute(object sender, object parameter)
+        {
+            if (string.IsNullOrEmpty(Text)) return null;
+            var dataPackage = new DataPackage { RequestedOperation = DataPackageOperation.Copy };
+            dataPackage.SetText(Text);
+            Clipboard.SetContent(dataPackage);
+            return null;
+        }
+    }
+}