Consolidate MU_CHANGEs in Memory Protection Code

Description

Many changes have been made to CoreInitializeMemoryProtection()
to improve the security state. It's gotten to the point that
the code has been essentially rewritten so to improve
readability and maintainability, consolidate the changes
to MemoryProtectionSupport.c (a Project Mu file).

- [x] Impacts functionality?
  - **Functionality** - Does the change ultimately impact how firmware functions?
  - Examples: Add a new library, publish a new PPI, update an algorithm, ...
- [ ] Impacts security?
  - **Security** - Does the change have a direct security impact on an application,
    flow, or firmware?
  - Examples: Crypto algorithm change, buffer overflow fix, parameter
    validation improvement, ...
- [ ] Breaking change?
  - **Breaking change** - Will anyone consuming this change experience a break
    in build or boot behavior?
  - Examples: Add a new library class, move a module to a different repo, call
    a function in a new library class in a pre-existing module, ...
- [ ] Includes tests?
  - **Tests** - Does the change include any explicit test code?
  - Examples: Unit tests, integration tests, robot tests, ...
- [ ] Includes documentation?
  - **Documentation** - Does the change contain explicit documentation additions
    outside direct code modifications (and comments)?
  - Examples: Update readme file, add feature readme file, link to documentation
    on an a separate Web page, ...

How This Was Tested

Tested by booting to Windows on Q35 and and booting to shell
on SBSA

Integration Instructions

N/A

MdeModulePkg/Core/Dxe/DxeMain.h

@@ -2699,7 +2699,8 @@ CoreInitializeMemoryAttributesTable (
 **/
 VOID
 EFIAPI
-CoreInitializeMemoryProtection (
+// MU_CHANGE: Use Project Mu CoreInitializeMemoryProtection()
+CoreInitializeMemoryProtectionMu (
   VOID
   );
 

MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c

@@ -479,7 +479,7 @@ DxeMain (
   MemoryProfileInstallProtocol ();
 
   CoreInitializeMemoryAttributesTable ();
-  CoreInitializeMemoryProtection ();
+  CoreInitializeMemoryProtectionMu (); // MU_CHANGE: Use Project Mu CoreInitializeMemoryProtection()
 
   //
   // Get persisted vector hand-off info from GUIDeed HOB again due to HobStart may be updated,