Implemented Donate page with wirking (?) in app purchases

Moved Pages to Views

ModernKeePass/ViewModels/DonateVm.cs

@@ -0,0 +1,38 @@
+using System.Collections.ObjectModel;
+using System.Globalization;
+using System.Linq;
+using System.Threading.Tasks;
+using Windows.ApplicationModel.Store;
+using ModernKeePass.Common;
+using ModernKeePass.Interfaces;
+using ModernKeePass.Services;
+
+namespace ModernKeePass.ViewModels
+{
+    public class DonateVm: NotifyPropertyChangedBase
+    {
+        public ObservableCollection<ProductListing> Donations { get; }
+
+        public ProductListing SelectedItem
+        {
+            get { return _selectedItem; }
+            set { SetProperty(ref _selectedItem, value); }
+        }
+
+        private readonly ILicenseService _license;
+        private ProductListing _selectedItem;
+
+        public DonateVm() : this (new LicenseService()) { }
+
+        public DonateVm(ILicenseService license)
+        {
+            _license = license;
+            Donations = new ObservableCollection<ProductListing>(_license.Products.Values.OrderBy(p => /*decimal.Parse(*/p.FormattedPrice/*, NumberStyles.Currency | NumberStyles.AllowDecimalPoint)*/));
+        }
+
+        public async Task<int> Purchase()
+        {
+            return await _license.Purchase(SelectedItem.ProductId);
+        }
+    }
+}