Reorganize profilers into dedicated subpages.

[Ivorforce]

• Follow-up of Add documentation on how to use Tracy and Perfetto #11484

Current	After

Moves Using C++ Profilers out of Debugging and gives each profiler a dedicated page.

Reasoning

We now support Instruments as a tracing profiler, and it no longer neatly fits into either "tracing profilers" or "sampling profilers". (Tracy can also do both, though I don't know if it can do sampling without tracing)

I think it makes more sense to introduce and weigh profilers all on the same page, since this is where people will be deciding which profiler to use.
When they have decided, they can visit the appropriate profiler sub-page to get dedicated instructions, as well as fitting per-profiler discussions in the comments.

I didn't change the individual profiler instructions, except rebrand HotSpot appropriately to Hotspot (as on their own page) and add a seealso at the top of each page.

[AThousandShips]

Will take a closer pass at the wording soon, but great improvement!