Add `cuda::std::is_sufficiently_aligned` and consider deprecating `cuda::is_aligned`

@mhoemmen made me aware of C++26's [`cuda::std::is_sufficiently_aligned`](https://en.cppreference.com/w/cpp/memory/is_sufficiently_aligned.html), which we regularly need in our code., so we should implement it.

We already have `cuda::is_aligned`, which differs that it takes the alignment as function parameter instead of as a template parameter. We should decide to keep or deprecate it.