MdeModulePkg: StatusCodeHandler: StatusCodeHandler driver in StandaloneMm

This change added support of StandaloneMm for StatusCodeHandler. It
adds a new instance of StatusCodeHandler of MM_STANDALONE type, and
abstracts the driver entrypoint into separate files, replaced gSmst with
gMmst, and switched to MM version of RscHandlerProtocol.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Dandan Bi <dandan.bi@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Jiewen Yao <jiewen.yao@intel.com>

Signed-off-by: Kun Qin <kun.q@outlook.com>
Reviewed-by: Hao A Wu <hao.a.wu@intel.com>

MdeModulePkg/Universal/StatusCodeHandler/Smm/StatusCodeHandlerTraditional.c

@@ -0,0 +1,31 @@
+/** @file
+  Abstraction layer that contains Standalone MM specific implementation for
+  Status Code Handler Driver.
+
+  Copyright (c) Microsoft Corporation.
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "StatusCodeHandlerMm.h"
+
+/**
+  Entry point of Traditional MM Status Code Driver.
+
+  This function is the entry point of Traditional MM Status Code Driver.
+
+  @param  ImageHandle       The firmware allocated handle for the EFI image.
+  @param  SystemTable       A pointer to the EFI System Table.
+
+  @retval EFI_SUCCESS       The entry point is executed successfully.
+
+**/
+EFI_STATUS
+EFIAPI
+StatusCodeHandlerTraditionalMmEntry (
+  IN EFI_HANDLE         ImageHandle,
+  IN EFI_SYSTEM_TABLE   *SystemTable
+  )
+{
+  return StatusCodeHandlerCommonEntry ();
+}