hardware device performance test and data collection

[diablodale]

DO NOT MERGE First, this PR is first intended to demonstrate issue #415. 👍 Second, I would like to see an evolved version of this PR to be later merged after discussion on its usage/value. ⏳

• adds a new performance test tests/hardware_cputemp_perf.cpp
• written for C++17 -- can't be bothered to make it work with earlier
• updates Flags.cmake to discover the compiler's range of support for C++ standards
• updates cmake for tests so can specify the c++ standard for any test and the cmake harness will do the right thing

[diablodale]

Sorry, I might not have been clear enough. The test in this PR is not designed for today's CI to run the test. Build will hopefully work. But probably not run. Because on an OAK-D it takes 3 hours for that one test exe. And it writes the collected metrics into the same directory as the exe, so it needs write access to that location.

I recommend you use CI or your own local toolkit to build. And then run the test yourself.

If you have a method in which your CI can run a test for 3 hours (oak-d) or probably a day (for PoE if it ever works), then I'm happy to adapt the code. I can also add whatever is necessary so that the performance metrics are written/collected.