[Improve] Use the official NVTX C++ API once available.

[gigony]

Is your feature request related to a problem? Please describe.

Since C++ helper classes in NVTX exists on dev branch only and they are not merged into main branch, cuCIM is using a latest dev branch commit (https://github.com/NVIDIA/NVTX/tree//3c98c8425b0376fd8653aac7cfc6a864f3897752/cpp) to use the helper classes.

To import a specific commit (instead of branch/tag), the full git repository is cloned.

if (NOT TARGET deps::nvtx3)
    FetchContent_Declare(
            deps-nvtx3
            GIT_REPOSITORY https://github.com/NVIDIA/NVTX.git
            GIT_TAG 3c98c8425b0376fd8653aac7cfc6a864f3897752
            # GIT_SHALLOW TRUE  # Uncomment this when the official release of nvtx3-cpp is available.
            ...

We need to uncomment the line once nvtx3-cpp is available.

Describe the solution you'd like

Uncomment the line ( # GIT_SHALLOW TRUE ) and use a specific tag once nvtx3-cpp is available.

Additional context

Should we raise an issue to track this?

Originally posted by @jakirkham in #144 (comment)

[jakirkham]

Think this might be doable now. Though we should double check