Enable CUDA profiling during with statement.

This function enables profiling on entering a with statement, and disables profiling on leaving the statement.

>>> with cupyx.profiler.profile():
...    # do something you want to measure
...    pass


When starting nvprof from the command line, manually setting --profile-from-start off may be required for the desired behavior. Likewise, when using nsys profile setting -c cudaProfilerApi may be required.