add(Friend)：添加好友相关逻辑

backend/IM_API/Dtos/FriendDto.cs

@@ -3,4 +3,5 @@
 namespace IM_API.Dtos
 {
     public record FriendInfoDto(int Id, int UserId,int FriendId,FriendStatus StatusEnum,DateTime Created,string RemarkName,string? Avatar);
+    public record FriendRequestHandleDto(HandleFriendRequestAction action,string? remarkName);
 }

backend/IM_API/Dtos/FriendRequestDto.cs

@@ -4,6 +4,7 @@
     {
         public int FromUserId { get; set; }
         public int ToUserId { get; set; }
+        public string? RemarkName { get; set; }
         public string? Description { get; set; }
     }
 }

backend/IM_API/Dtos/HandleFriendRequestDto.cs

@@ -10,6 +10,10 @@
         /// 处理操作
         /// </summary>
         public HandleFriendRequestAction Action { get; set; }
+        /// <summary>
+        /// 好友备注名
+        /// </summary>
+        public string? RemarkName { get; set; }
     }
     public enum HandleFriendRequestAction
     {