Add a simplified storage common header just like the rest.

[ahsonkhan]

Is the header files in azure-storage-common meant to be public and used by end users? Do we apply the same breaking change bar to them as our other public headers? If so, we may want to add a simplified header for it, just like:

azure-sdk-for-cpp/sdk/storage/azure-storage-files-datalake/inc/azure/storage/files/datalake.hpp

Line 6 in 36ea25d

#include "azure/storage/files/datalake/datalake_directory_client.hpp"

azure-sdk-for-cpp/sdk/storage/azure-storage-files-shares/inc/azure/storage/files/shares.hpp

Line 6 in 36ea25d

#include "azure/storage/files/shares/share_client.hpp"

azure-sdk-for-cpp/sdk/storage/azure-storage-blobs/inc/azure/storage/blobs.hpp

Line 6 in 36ea25d

#include "azure/storage/blobs/append_blob_client.hpp"

Maybe in azure-sdk-for-cpp\sdk\storage\azure-storage-common\inc\azure\storage\common.hpp:

// Copyright (c) Microsoft Corporation. All rights reserved.
// SPDX-License-Identifier: MIT

#pragma once

#include "azure/storage/common/access_conditions.hpp"
#include "azure/storage/common/account_sas_builder.hpp"
#include "azure/storage/common/concurrent_transfer.hpp"
#include "azure/storage/common/constants.hpp"
#include "azure/storage/common/crypt.hpp"
#include "azure/storage/common/file_io.hpp"
#include "azure/storage/common/json.hpp"
#include "azure/storage/common/reliable_stream.hpp"
#include "azure/storage/common/shared_key_policy.hpp"
#include "azure/storage/common/storage_common.hpp"
#include "azure/storage/common/storage_credential.hpp"
#include "azure/storage/common/storage_error.hpp"
#include "azure/storage/common/storage_per_retry_policy.hpp"
#include "azure/storage/common/storage_retry_policy.hpp"
#include "azure/storage/common/xml_wrapper.hpp"

cc @katmsft, @Jinming-Hu, @JeffreyRichter