misc: move Models & Helpers into Common & Avalonia projects

src/Ryujinx/Common/Models/Amiibo/AmiiboJson.cs

@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Text.Json.Serialization;
+
+namespace Ryujinx.Ava.Common.Models.Amiibo
+{
+    public struct AmiiboJson
+    {
+        [JsonPropertyName("amiibo")]
+        public List<AmiiboApi> Amiibo { get; set; }
+        [JsonPropertyName("lastUpdated")]
+        public DateTime LastUpdated { get; set; }
+    }
+}