feat：【SYSTEM】通过系统配置管理来设置系统是否可注册用户

yudao-module-system/yudao-module-system-api/src/main/java/cn/iocoder/yudao/module/system/enums/ErrorCodeConstants.java

@@ -45,6 +45,7 @@ public interface ErrorCodeConstants {
     ErrorCode USER_COUNT_MAX = new ErrorCode(1_002_003_008, "创建用户失败，原因：超过租户最大租户配额({})！");
     ErrorCode USER_IMPORT_INIT_PASSWORD = new ErrorCode(1_002_003_009, "初始密码不能为空");
     ErrorCode USER_MOBILE_NOT_EXISTS = new ErrorCode(1_002_003_010, "该手机号尚未注册");
+    ErrorCode USER_REGISTER_DISABLED = new ErrorCode(1_002_003_011, "注册功能已关闭");
 
     // ========== 部门模块 1-002-004-000 ==========
     ErrorCode DEPT_NAME_DUPLICATE = new ErrorCode(1_002_004_000, "已经存在该名字的部门");