Noir::RustRequestGuards::Facts

A guard impl file's use crate::...; statements, parsed for their names (Error => crate::error::Error) only when an enum is ambiguous.

crate|Enum => the files of that crate that define enum Enum.

Enum::Variant keys a status_code arm maps to 401/403, and those some arm maps to another status (a key in both is not trusted).

The same arms from every status-mapping fn, keyed scope|Enum::Variant with scope f:<file> and c:<crate dir>; scope|Enum for an enum some arm there maps, and for one whose match self has a catch-all arm (_ =>) answering another status.