KW36 QPP pass through profile reference code

[#1]

In BLE spec there is no standard wireless pass through profile, so different chip vendors have their own implementations, which is also called Proprietary Profile, the compatibility is a big challenge.
There are two wireless pass through demos in NXP BLE demos. For QN90XX chip, it’s called QPP. For KW3X, it’s called wireless UART. The wireless UART is more complex. It doesn’t support always-connection and have many limitations for the app. The common BLE debug tool app on phone side cannot communicate with it, while the QPP can work well. 
This demo code is target to port the QPP profile to KW3X SDK, which can simplify user’s development.