add(AuthController):新增鉴权控制器

fix(model):修复数据库字段映射问题

backend/IM_API/Configs/MapperConfig.cs

@@ -0,0 +1,14 @@
+using AutoMapper;
+using IM_API.Dtos;
+using IM_API.Models;
+
+namespace IM_API.Configs
+{
+    public class MapperConfig:Profile
+    {
+        public MapperConfig()
+        {
+            CreateMap<User, UserInfoDto>();
+        }
+    }
+}