refactor<*>: rewrite all with AvaloniaUI

src/ViewModels/DropStash.cs

@@ -0,0 +1,22 @@
+using System.Threading.Tasks;
+
+namespace SourceGit.ViewModels {
+    public class DropStash : Popup {
+        public Models.Stash Stash { get; private set; }
+
+        public DropStash(string repo, Models.Stash stash) {
+            _repo = repo;
+            Stash = stash;
+            View = new Views.DropStash() { DataContext = this };
+        }
+
+        public override Task<bool> Sure() {
+            return Task.Run(() => {
+                new Commands.Stash(_repo).Drop(Stash.Name);
+                return true;
+            });
+        }
+
+        private string _repo;
+    }
+}