Edit prop279 to support alternative name representations and non-English languages

Attached is a git diff patch with edits to torspec.git/proposals/279-naming-layer-api.txt (patch on 13cbcbc). Inspired by discussion on tor-dev:

Brief conceptual overview of the most significant changes:

Support Name System API plugins which transform self-contained alternative representations of the data in .onion names. These can be safely configured for a global wildcard '*', then sandboxed with neither network nor filesystem access.
Add UTF-8 support, so as not restrict the Name System API to users of American English.
Specify failure status codes which will cause name resolution attempts to stop, even if the name may match the TLD for other plugins at a lower priority. This is useful if a plugin configured for a '*' TLD definitively recognizes that a name is invalid, e.g. due to checksum failure.
Other changes which support the foregoing objectives.

Please review and commit.

Trac:
Username: nullius

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