MdeModulePkg/DxeCore: merge properties table routines into MAT handling

MdeModulePkg/DxeCore: merge properties table routines into MAT handling

The memory attributes table handling code shared some parts of the
properties table handling code when it was introduced. The latter has
been dropped, and so we can merge the remaining pieces into the former.

Link: https://bugzilla.tianocore.org/show_bug.cgi?id=2633
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
Reviewed-by: Bret Barkelew <bret.barkelew@microsoft.com>
Acked-by: Jiewen Yao <Jiewen.yao@intel.com>
Acked-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Dandan Bi <dandan.bi@intel.com>
Reviewed-by: Jian J Wang <jian.j.wang@intel.com>