Add CVE and CWE roles

[hugovk]

Subject:

Feature or Bugfix

• Feature

Purpose

• Add a cve role to turn :cve:`2020-10735` into https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-10735
• Add a cwe role to turn :cwe:`787` into https://cwe.mitre.org/data/definitions/787.html

Detail

• Add cve and cwe roles, similar to existing pep and rfc roles, to link to the Common Vulnerabilities and Exposures and Common Weakness Enumeration websites.

Relates

• https://github.com/sphinx-doc/sphinx/pull/11780

[AA-Turner]

No objection in principle, though this feels like a feature is missing to make this easier -- these roles are just extlinks, in bold, with customised classes ('cve'/'cwe') and index entries.

A

[picnixz]

We could refactor this by adding a class reponsible for this kind of things maybe?