Adds a new library instance to support MM core functionality for
performance in Standalone MM.
- Add StandaloneMmCorePerformanceLib instance
- Move common MM logic to a new file `MmCorePerformanceLib.c`
- Define interfaces with implementation specific to MM environment
type in `SmmCorePerformanceLibInternal.h` and implement those
functions in the Standalone MM and Traditional MM specific C files
Note: StandaloneMmCorePerformanceLib supports both
`MM_CORE_STANDALONE` and `MM_STANDALONE` as some Standalone MM
environments have privilege separation and need to link this
functionality in a ring 3 Standalone MM driver that is outside
the ring 0 Standalone MM core driver.
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>