submodule对gitea不管用，所以直接拉了一份拉格兰

Lagrange.Core/Lagrange.OneBot/Core/Entity/OneBotFriend.cs

@@ -0,0 +1,17 @@
+using System.Text.Json.Serialization;
+
+namespace Lagrange.OneBot.Core.Entity;
+
+[Serializable]
+public class OneBotFriend
+{
+    [JsonPropertyName("user_id")] public uint UserId { get; set; }
+
+    [JsonPropertyName("q_id")] public string? QId { get; set; }
+
+    [JsonPropertyName("nickname")] public string NickName { get; set; } = "";
+
+    [JsonPropertyName("remark")] public string Remark { get; set; } = "";
+    
+    [JsonPropertyName("group")] public OneBotFriendGroup? Group { get; set; }
+}