Added dirty behavior

Removed restore action (-> Move action wip)
Added additional check on DB size before auto saving
Code cleanup

ModernKeePass.Application/Database/Models/DatabaseVm.cs

@@ -10,5 +10,7 @@
         public string Compression { get; set; }
         public string CipherId { get; set; }
         public string KeyDerivationId { get; set; }
+        public int Size { get; internal set; }
+        public bool IsDirty { get; internal set; }
     }
 }