Moves the six WoWee Content Pack (.wcp) handlers out of
main.cpp:
--list-wcp --info-wcp
--info-pack-budget --info-pack-tree
--pack-wcp --unpack-wcp
All six defer to wowee::editor::ContentPacker for actual pack
I/O; the handlers just parse args and format output, so the
extraction has no behavioral impact on the pack format itself.
main.cpp drops 17,766 → 17,505 lines (-261). Behavior verified
by re-running --info-wcp on a missing file (same error message).
