Improvements to CPU profiler

[OleksandrChekhovskyi]

Expose more useful data from node.js

[OleksandrChekhovskyi]

Some builds are failing because of errors downloading node.js releases, not because of problems with patches.

[3y3]

@OleksandrChekhovskyi , thank you for contribution.
Please look at my inline comments.

[OleksandrChekhovskyi]

I have updated the first patch, because I've noticed a compiler warning in CI builds. Also see my replies to inline comments.

Edit: For some reason, GitHub does not show 'commented on outdated diff' in this PR. Did you comment not from PR? It looks like it just lost the comments after force push, unfortunately.
You will probably still see replies in the email, but the important part was that v8::CpuProfiler::StopProfiling stops the last active profile in case of name being an empty string. That's why there are checks for name being empty.

[3y3]

Reasonable comments.
Landed as 510542c