MdePkg/BaseLib: Introduce CharToUpper and AsciiCharToUpper publicly

MdePkg/BaseLib: Introduce CharToUpper and AsciiCharToUpper publicly

Introduce two public functions CharToUpper and AsciiCharToUpper.
They have the same functions as InternalCharToUpper and
InternalBaseLibAsciiToUpper.Considering the internal functions will
be removed,so directly I change their function names to the public ones'.
https://bugzilla.tianocore.org/show_bug.cgi?id=1369

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Shenglei Zhang <shenglei.zhang@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>