This creates a generic interface that FEXCore can use for timeline
profiling. This allows us to create a generic interface which the
backend details are hidden so we can support multiple timeline profile
APIs.
The only API supported right now is ftrace/gpuvis. Which is extremely
lightweight of an interface with minimal overhead.
We must be careful here since in most cases will will have dozens of
FEX instances running at any given time. So a timeline profiler like
Microprofiler can have major issues since that only ever expects a
single process at a time.
Not enabled by default but just needs the `ENABLE_FEXCORE_PROFILER`
cmake option set to enable.