HTTP APICloud StoragePG Cloud StorageObject生成签名上传 URL生成签名上传 URL POST /v1/storages/object/upload/sign/:bucketId/:objectName 生成有时效的签名上传 URL，允许客户端无需直接认证即可上传文件。 Request Responses200400成功参数错误 / 或缺少 Authorization 头（message: headers must have required property 'authorization'）