feature: add flower

FlowerApp/Data/Model/FlowerItem.cs

@@ -41,4 +41,10 @@ public class FlowerItem
 
     [Ignore]
     public int? Distance { get; set; }
+
+    public override string ToString()
+    {
+        // TODO:
+        return $"id: {Id}, owner: {OwnerId}, category: {CategoryId}, name: {Name}, date: {DateBuyUnixTime}, ...";
+    }
 }