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/Exceptions/BaseException.cs

@@ -0,0 +1,17 @@
+using IM_API.Tools;
+
+namespace IM_API.Exceptions
+{
+    public class BaseException:Exception
+    {
+        public int Code { get; set; }
+
+        public BaseException(int code,string message) : base(message) { 
+            this.Code = code;
+        }
+        public BaseException(CodeDefine codeDefine) : base(codeDefine.Message)
+        {
+            this.Code = codeDefine.Code;
+        }
+    }
+}