[Base] Add user-literals for several memory sizes

[Wunkolo]

Rather than using n * 1024 * 1024, this adds a convenient _MiB/_KiB user-literal to the new literals.h header to concisely describe units of memory in a much more readable way. Any other useful literals can be added to this header. These literals exist in the xe::literals namespace so they are opt-in, similar to std::chrono literals, and require a using namespace xe::literals statement to utilize it within the current scope.

I've done a pass through the codebase to replace trivial instances of 1024 * 1024 * ... expressions being used but avoided anything that added additional casting complexity from size_t to uint32_t and such to keep this commit concise.

[Razzile]

This is a cool feature of C++ i didn't know about. I vaguely remember seeing custom literals for strings but had no idea it could be applied to other types as well

[dentiny]

I think you can also add floating points?

constexpr unsigned long long operator""_PiB(long double sz) {
  const long double res = sz * 1024ULL * 1024ULL * 1024ULL * 1024ULL * 1024ULL;
  return static_cast<unsigned long long>(res);
}
constexpr unsigned long long operator""_PB(long double sz) {
  const long double res = sz * 1000ULL * 1000ULL * 1000ULL * 1000ULL * 1000ULL;
  return static_cast<unsigned long long>(res);
}

constexpr unsigned long long operator""_TiB(long double sz) {
  const long double res = sz * 1024ULL * 1024ULL * 1024ULL * 1024ULL;
  return static_cast<unsigned long long>(res);
}
constexpr unsigned long long operator""_TB(long double sz) {
  const long double res = sz * 1000ULL * 1000ULL * 1000ULL * 1000ULL;
  return static_cast<unsigned long long>(res);
}

constexpr unsigned long long operator""_GiB(long double sz) {
  const long double res = sz * 1024ULL * 1024ULL * 1024ULL;
  return static_cast<unsigned long long>(res);
}
constexpr unsigned long long operator""_GB(long double sz) {
  const long double res = sz * 1000ULL * 1000ULL * 1000ULL;
  return static_cast<unsigned long long>(res);
}

constexpr unsigned long long operator""_MiB(long double sz) {
  const long double res = sz * 1024ULL * 1024ULL;
  return static_cast<unsigned long long>(res);
}
constexpr unsigned long long operator""_MB(long double sz) {
  const long double res = sz * 1000ULL * 1000ULL;
  return static_cast<unsigned long long>(res);
}

constexpr unsigned long long operator""_KiB(long double sz) {
  const long double res = sz * 1024ULL;
  return static_cast<unsigned long long>(res);
}
constexpr unsigned long long operator""_KB(long double sz) {
  const long double res = sz * 1000ULL;
  return static_cast<unsigned long long>(res);
}

constexpr unsigned long long operator""_B(unsigned long long sz) { return sz; }