feat(upload): 添加华为 OBS 对象存储支持

- 在 addons.php 中添加了与华为 OBS 相关的钩子
- 新增了对华为 OBS 上传功能的实现，包括分片上传和合并
- 优化了上传参数处理和错误处理
- 支持客户端和服务端两种上传模式

addons/hwobs/library/Obs/Internal/Resource/OBSConstants.php

@@ -0,0 +1,35 @@
+<?php
+
+/**
+ * Copyright 2019 Huawei Technologies Co.,Ltd.
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use
+ * this file except in compliance with the License.  You may obtain a copy of the
+ * License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed
+ * under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+ * CONDITIONS OF ANY KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations under the License.
+ *
+ */
+
+namespace Obs\Internal\Resource;
+
+class OBSConstants extends Constants {
+    const FLAG = 'OBS';
+    const METADATA_PREFIX = 'x-obs-meta-';
+    const HEADER_PREFIX = 'x-obs-';
+    const ALTERNATIVE_DATE_HEADER = 'x-obs-date';
+    const SECURITY_TOKEN_HEAD = 'x-obs-security-token';
+    const TEMPURL_AK_HEAD = 'AccessKeyId';
+    
+    const COMMON_HEADERS = [
+        'content-length' => 'ContentLength',
+        'date' => 'Date',
+        'x-obs-request-id' => 'RequestId',
+        'x-obs-id-2' => 'Id2',
+        'x-reserved' => 'Reserved'
+    ];
+}