Adding initial auction system

Models/DTOs/BidRequest.cs

@@ -0,0 +1,7 @@
+namespace GameAuthApi.Models;
+
+public class BidRequest
+{
+    public string AuctionId { get; set; }
+    public int BidAmount { get; set; }
+}

Models/DTOs/CreateAuctionRequest.cs

@@ -0,0 +1,7 @@
+namespace GameAuthApi.Models;
+
+public class CreateAuctionRequest
+{
+    public string ItemId { get; set; }
+    public int StartingPrice { get; set; }
+}