Create database works with new Vm

Refactoring

WinAppCommon/ViewModels/AboutVm.cs

@@ -0,0 +1,27 @@
+using Windows.ApplicationModel;
+
+namespace ModernKeePass.ViewModels
+{
+    public class AboutVm
+    {
+        private readonly Package _package;
+
+        public string Name => _package.DisplayName;
+
+        public string Version
+        {
+            get
+            {
+                var version = _package.Id.Version;
+                return $"{version.Major}.{version.Minor}";
+            }
+        }
+
+        public AboutVm() : this(Package.Current) { }
+
+        public AboutVm(Package package)
+        {
+            _package = package;
+        }
+    }
+}