BaseTools: Add check for the string type whether is same

BaseTools: Add check for the string type whether is same

Relational and equality operators require both operands to be of
the same type.
Treat the string 'A' and "A" as same type, but for "A" and L"A"
are not same type since one is general string, another is unicode
string.

True:'A'<'B', "A"<"B" 'A'<"B", L'A'<L'B', L"A"<L"B", L'A'<L"B"
Error:'A'<L'B', 'A'<L"B", "A'<L'B'

Cc: Liming Gao <liming.gao@intel.com>
Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Zhiju.Fan <zhijux.fan@intel.com>
Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>