兼容shiro获取用户API写法，适配online底层lib依赖

jeecg-boot/jeecg-boot-base-core/src/main/java/org/apache/shiro/SecurityUtils.java

@@ -0,0 +1,21 @@
+package org.apache.shiro;
+
+import org.apache.shiro.subject.Subject;
+
+/**
+ * 兼容处理Online功能使用处理，请勿修改
+ * @author eightmonth@qq.com
+ * @date 2024/4/29 14:05
+ */
+public class SecurityUtils {
+
+
+    public static Subject getSubject() {
+        return new Subject() {
+            @Override
+            public Object getPrincipal() {
+                return Subject.super.getPrincipal();
+            }
+        };
+    }
+}

jeecg-boot/jeecg-boot-base-core/src/main/java/org/apache/shiro/subject/Subject.java

@@ -0,0 +1,15 @@
+package org.apache.shiro.subject;
+
+
+import org.jeecg.common.util.LoginUserUtils;
+
+/**
+ * 兼容处理Online功能使用处理，请勿修改
+ * @author eightmonth@qq.com
+ * @date 2024/4/29 14:18
+ */
+public interface Subject {
+    default Object getPrincipal() {
+        return LoginUserUtils.getSessionUser();
+    }
+}