Add craft-doc-binary: WordCraft's .doc reader on craft-wordmodel and craft-cfb
* craft-doc-binary: WordCraft's crates/docbin as it is at wordcraft 07f97737
The source, unchanged, so the next commit shows only what the move changes.
It has no manifest yet, so it is not built.
* craft-doc-binary: on craft-wordmodel, craft-cfb and craft-codepage
- The compound file is read with craft-cfb (bounded directory, streams refused
above 1 GiB before anything is allocated), in place of the cfb crate and
WordCraft's cfb_guard precheck; an oversized stream is DocbinError::Limit.
- 8-bit text uses craft-codepage in place of wordcraft_doc::encoding.
- wordcraft-doc is craft-wordmodel; wordcraft-geom's helpers are its geom.
The tests keep building their files with the cfb crate (a dev-dependency), so
craft-cfb's reader is checked against another implementation's writer. The
repeating-DIFAT regression is craft-cfb's own; the guard asserts in the
valid-files test go with the guard.
