In order to prevent incorrect link time optimizations with taskController.cpp
and address sanitizer, unitTestDelegate subclasses the necessary HdxTasks

HD_TRACE_FUNCTION and HF_MALLOC_TAG_FUNCTION macros have been relocated into _TrackDelegateTask
The _TrackDelegateTask function now accepts a task creation function to create the actual HdTask
This prevents a weird link-time optimization error when building with address sanitizers