add FaceRecognitionEngine, face recognition json result, and TCs

add FaceRecognitionEngine, face recognition json result, and TCs

This patch is added FaceRecognitionEngine which handle face recognition event.
The logic for using FaceRecognitionEngine is in mmi_iu module.
Also, it added creating json result logic about face recognition event's result.
Then, it can check it's working by adding test case which get result from face recognition event.

Change-Id: I43cf857b341f064f0d173eb71fbd1e361ee3567a