Add support for concepts

[BenjaminW3]

gcc and clang support preliminary versions of the concepts TS that can be enabled with -fconcepts
With this we could describe the concepts Pltf, Dev, Acc, Stream, Buf, View, etc. to make the code better understandable and to get much more clear error messages.

[bernhardmgruber]

By now, concepts should be supported in mainline gcc, clang and MSVC.

[sbastrakov]

And alpaka has own concepts. Which are of course not as functional as the standard ones, but are still very useful imo

[bernhardmgruber]

I think C++20 is available enough to start working on this. We could still #ifdef the concept checks in template heads away, but provide them if the compiler supports it. LLAMA does the same for a while now and it works without any troubles.

Since @j-stephan mentioned interest in this several times in the past, I will assign this to him :)

[fwyzard]

I'm all in favour of adopting concepts in Alpaka, but please keep it and the c++20 requirement optional, as the CMS software cannot switch to c++20 yet :(

Also, c++20 requires CUDA 12.x, for which we still have some open but reports :(