fix: homogenize authoring format and place (#7034)

* fix: homogenize authors format and place

- use colon as author separator (replaces `&`, `and`, `y`, `e`, `et`...)
- ensures is placed after resource title, not part of itself `title - author`
- `et al.` as special author/token to group many

* remove double comma

* fix: recover traducer role notations as `trad.:`

* detect and apply some `trad.:`s role anotation

* chore: `trad.:` to `trl.:`

Apply suggestion made by Eric at https://github.com/EbookFoundation/free-programming-books/pull/7034#discussion_r954014539

Co-authored-by: Eric Hellman <eric@hellman.net>

* Sort author - format

* fix: remove empty authors (dash is alone)

Used regex: `-\s+(\(|$)`

* format: change to `edt.:` role

Definition list at https://www.loc.gov/marc/relators/relaterm.html

Co-authored-by: Eric Hellman <eric@hellman.net>

courses/free-courses-es.md

@@ -71,7 +71,7 @@
 * [Fundamentos de Comunicaciones Ópticas](https://www.edx.org/course/fundamentos-de-comunicaciones-opticas-upvalenciax-fco201x-1)
 * [Fundamentos de Informática (2008)](http://ocw.bib.upct.es/course/view.php?id=112)
 * [Fundamentos Físicos de la Informática (2010)](http://ocw.uv.es/ingenieria-y-arquitectura/1-4/Course_listing)
-* [Informática - algoritmos y aritmética- (2012)](http://ocw.uv.es/ciencias/informatica-1/Course_listing)
+* [Informática -algoritmos y aritmética- (2012)](http://ocw.uv.es/ciencias/informatica-1/Course_listing)
 * [Ingieniería Electrónica y Automática - PLC (2014)](http://isa.uniovi.es/docencia/iea/)
 * [Laboratorio de Comunicaciones (2008)](http://ocw.bib.upct.es/course/view.php?id=80)
 * [Lenguajes unificado de modelado: UML (2016)](https://campusvirtual.ull.es/ocw/course/view.php?id=132)