MdePkg: Add Google Mock Library for SmmMemLib

[SeolforHsieh]

MockSmmMemLib for google test

Description

MockSmmMemLib for google test

• Breaking change?
  • Breaking change - Does this PR cause a break in build or boot behavior?
  • Examples: Does it add a new library class or move a module to a different repo.
• Impacts security?
  • Security - Does this PR have a direct security impact?
  • Examples: Crypto algorithm change or buffer overflow fix.
• Includes tests?
  • Tests - Does this PR include any explicit test code?
  • Examples: Unit tests or integration tests.

How This Was Tested

Unit tests component can call these mock functions success

Integration Instructions

N/A