fix: 为xdz-module-platform-server模块添加Spring Boot主类

- 创建PlatformServerApplication主类，解决spring-boot-maven-plugin无法找到主类的编译错误
- 主类路径: com.xindazhou.platform.PlatformServerApplication

xdz-module-platform/xdz-module-platform-server/src/main/java/com/xindazhou/platform/PlatformServerApplication.java

@@ -0,0 +1,19 @@
+package com.xindazhou.platform;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+/**
+ * Platform 服务启动类
+ *
+ * @author 新大洲
+ */
+@SpringBootApplication
+public class PlatformServerApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(PlatformServerApplication.class, args);
+    }
+
+}
+