BaseTools ConvertMasmToNasm: Fix exception when no arguments are given

BaseTools ConvertMasmToNasm: Fix exception when no arguments are given

Convert to use the argparse library rather than optparse.

As part of the conversion, the script will now give an error message
if no arguments are given. Previously the script would give an
exception when no arguments were given.

Fixes: https://github.com/tianocore/edk2/issues/65
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>