Revalidate unAPI status codes

[vanch3d]

Both /unapi and /unapi?id={pub}&format={format} with correct parameters are considered successful requests and currently respond with a 200 status.
The last version of the unAPI documentation has a cryptic comment:

302 Found for responses to the UNAPI?id=IDENTIFIER&format=FORMAT function which redirect
https://web.archive.org/web/20070107163855/http://unapi.info/specs/unapi-version-1.html

but no mention of redirection in the description of the body.
However, revision 1 of the documentation clearly states:

3. UNAPI?uri=URI&format=FORMAT
[...]
Redirects the user to the object specified by URI in the format specified by FORMAT. The content-type should be the content-type specified in the element within the unAPI format response for this format.
https://web.archive.org/web/20070102033638/http://unapi.info:80/specs/unapi-revision-1.html

/unapi?id={pub}&format={format} should be changed to 302

---

• validate all status codes
• fix the API handler
• fix Swagger accordingly
• fix all <abbr> identifiers in the templates

[vanch3d]

It will also help with the Swagger description (see #30), making sure every possible response schema is unique and has a unique code

[vanch3d]

<abbr> identifiers are still using the publication.id rather than publication.archive_location