Create a FreeRTOS compliant Priority Queue

[cjchanx]

PQueue.hpp / PQueue.cpp

• May need to have a specific type of object that it always takes, possibly a template class that simply wraps the template with the queue required data members (can refer to AvionicsSoftware/SimpleSectorStorage.hpp for an example)
• Use a combination of a FreeRTOS Queue, a FreeRTOS Mutex (to protect access to the priority queue data structure) and the Embedded Template Library (ETL) Priority Queue (or a custom priority if you choose) to create it