BaseTool/Pkcs7: Add TestRoot.cer.

BaseTool/Pkcs7: Add TestRoot.cer.

We add this binary data file for TestRoot.cer.
So that a platform may include this default file in FDF,
to check if the platform is using default test key,
or different production key.

Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Yonghong Zhu <yonghong.zhu@intel.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>