add(conversationSerivice):后端新增消息会话服务add(main)：完善主面板

backend/IM_API/Configs/ServiceCollectionExtensions.cs

@@ -12,6 +12,7 @@ namespace IM_API.Configs
             services.AddTransient<IUserService, UserService>();
             services.AddTransient<IFriendSerivce, FriendService>();
             services.AddTransient<IMessageSevice, MessageService>();
+            services.AddTransient<IConversationService, ConversationService>();
             services.AddSingleton<IJWTService, JWTService>();
             services.AddSingleton<IRefreshTokenService,RedisRefreshTokenService>();
             return services;