ethercat alignment check for reinterpret cast

[jbbjarnason]

          @jbbjarnason You are missing alignment check for reinterpret cast, on x86_64 it will work unaligned but will be slow, on some older arms it will just crash, on modern >= armv7 unaligned should work but same as on x64 very slow

And I would use some span_cast as below to avoid mistakes with size

template<typename T, typename... Args>
concept same_as_any_of = std::disjunction_v<std::is_same<T, Args>...>;

template<typename T>
concept byte_like = same_as_any_of<T, std::byte, char, uint8_t>;

template<typename T>
concept trivially_copyable_non_byte = std::is_trivially_copyable_v<T> && !byte_like<T>;

template<byte_like SrcType, trivially_copyable_non_byte DstType>
[[nodiscard]] 
constexpr auto span_cast(std::span<SrcType> src) -> std::span<const DstType> {
    assert((reinterpret_cast<std::uintptr_t>(src.data()) % alignof(DstType) == 0) && "Data must be aligned to the destination type");
    std::size_t dst_size = src.size_bytes() / sizeof(DstType);
    return {reinterpret_cast<const DstType*>(src.data()), dst_size};
}

Originally posted by @arturbac in #524 (comment)