Add nvtx support via DrHook

[pmarguinaud]

This PR plug the NVTX instrumentation into DrHook (PGI only). This is enabled by the two following environment variables :

• DR_HOOK=1
• DR_NVTX = 1

Example of nsys profile with DrHook/NVTX enabled :

[FussyDuck]

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1 out of 6 committers have signed the CLA.

:white_check_mark: pmarguinaud
:x: AlexandreMary
:x: dareg
:x: RyadElKhatibMF
:x: meteoea
:x: Louis Stuber

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