Add graph support

[matmanc]

CUDA Graph API seems a promising addition to the already existing cuda streams. Especially to mix host and device function in a complex order. Moreover, also HIP supports cuda graphs so it feels natural to extend cudawrappers to supports graph.

In this pull request the basic functionality of cuda graph api are introduced.

Clone and verify on a machine with an NVIDIA GPU

cd $(mktemp -d --tmpdir cudawrappers-XXXXXX)
git clone https://github.com/nlesc-recruit/cudawrappers .
git checkout <this-branch>
cmake -S . -B build -CD -DCUDAWRAPPERS_BUILD_TESTING=True
make -C build
make -C build format # Nothing should change
make -C build lint # linting is broken until we fix the issues (see #92)
build/tests/test_graph

Clone and verify on a machine with HIP and AMD GPU

git clone https://github.com/nlesc-recruit/cudawrappers .
git checkout <this-branch>
cmake -S . -B build -CD -DCUDAWRAPPERS_BUILD_TESTING=True -DCUDA_WRAPPERS_BACKEND_HIP=True
make -C build
make -C build format # Nothing should change
build/tests/test_graph

[csbnw]

Very nice addition to cudawrappers! I did a first pass over the changes and made some (minor) suggestions.