optimize: @servicemark 注解，移除value属性，code属性必填。

core-parent/core/src/main/java/icu/easyj/core/factory/ServiceInfo.java

@@ -49,7 +49,7 @@ public static <S> ServiceInfo<S> of(S service) {
 		}
 
 		ServiceMark mark = service.getClass().getAnnotation(ServiceMark.class);
-		String code = StringUtils.isNotBlank(mark.code()) ? mark.code() : mark.value();
+		String code = mark.code();
 		if (StringUtils.isBlank(code)) {
 			throw new IllegalArgumentException("service的@ServiceMark.code或@ServiceMark.value不能为空");
 		}

core-parent/core/src/main/java/icu/easyj/core/factory/ServiceMark.java

@@ -35,20 +35,12 @@
 public @interface ServiceMark {
 
 	/**
-	 * 服务代码（同 code 属性，设置一个即可，两个都设置时，优先读取 code 属性）
+	 * 服务代码
 	 * 注：大小写不敏感
 	 *
 	 * @return code 返回服务代码
 	 */
-	String value() default "";
-
-	/**
-	 * 服务代码（同 value 属性，设置一个即可，两个都设置时，优先读取 code 属性）
-	 * 注：大小写不敏感
-	 *
-	 * @return code 返回服务代码
-	 */
-	String code() default "";
+	String code();
 
 	/**
 	 * 是否默认服务

core-parent/core/src/test/java/icu/easyj/core/factory/TestServiceImplA.java

@@ -1,5 +1,5 @@
 package icu.easyj.core.factory;
 
-@ServiceMark(value = "A", isDefault = true)
+@ServiceMark(code = "A", isDefault = true)
 class TestServiceImplA implements ITestService {
 }

core-parent/core/src/test/java/icu/easyj/core/factory/TestServiceImplB1.java

@@ -1,5 +1,5 @@
 package icu.easyj.core.factory;
 
-@ServiceMark(value = "B", order = 1)
+@ServiceMark(code = "B", order = 1)
 class TestServiceImplB1 implements ITestService {
 }

core-parent/core/src/test/java/icu/easyj/core/factory/TestServiceImplB2.java

@@ -1,5 +1,5 @@
 package icu.easyj.core.factory;
 
-@ServiceMark(value = "B", order = 2)
+@ServiceMark(code = "B", order = 2)
 class TestServiceImplB2 implements ITestService {
 }