Implement the VSOP87D position model.

Changes for 0.006_01 - 2024-03-23

• Prefer Astro::Coord::ECI::Utils::gm_strftime to POSIX::strftime because the behavior of POSIX::strftime when formatting GMT changed in Perl 5.39.8, and is no longer compatible with the libc implementation, which does not alter the components given it.