MdeModulePkg/VarCheckPolicyLib: implement standalone MM version

This commit adds the VarCheckPolicyLib that will be able to
execute in the context of standalone MM.

Signed-off-by: Masahisa Kojima <masahisa.kojima@linaro.org>
Co-authored-by: Kun Qin <kun.q@outlook.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Sami Mujawar <sami.mujawar@arm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Supreeth Venkatesh <supreeth.venkatesh@arm.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>

MdeModulePkg/Library/VarCheckPolicyLib/VarCheckPolicyLib.inf

@@ -13,11 +13,13 @@
   MODULE_TYPE                    = DXE_RUNTIME_DRIVER
   VERSION_STRING                 = 1.0
   LIBRARY_CLASS                  = NULL|DXE_RUNTIME_DRIVER DXE_SMM_DRIVER
-  CONSTRUCTOR                    = VarCheckPolicyLibConstructor
+  CONSTRUCTOR                    = VarCheckPolicyLibTraditionalConstructor
 
 
 [Sources]
   VarCheckPolicyLib.c
+  VarCheckPolicyLibTraditional.c
+  VarCheckPolicyLib.h
 
 
 [Packages]
@@ -29,7 +31,6 @@
   BaseLib
   DebugLib
   BaseMemoryLib
-  DxeServicesLib
   MemoryAllocationLib
   VarCheckLib
   VariablePolicyLib