BaseTools/PatchCheck.py: Add warning info for new binary files

BaseTools/PatchCheck.py: Add warning info for new binary files

The commit adds the detection of adding new binary files in a patch file
or in a commit.

The following warning messages will be appended at the end of the script
output:

WARNING - The following binary files will be added into the repository:
  <BinaryFile1>
  <BinaryFile2>
  ...

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>