[libcxx] adds std::ranges::swap, std::swappable, and std::swappable_with

Implements parts of:
    - P0898R3 Standard Library Concepts
    - P1754 Rename concepts to standard_case for C++20, while we still can

Depends on D96742

Differential Revision: https://reviews.llvm.org/D97162

GitOrigin-RevId: c7443327930d1a045abf784615686c1226cdaade
5 files changed