devel/sfml: Update to 3.0.0; migrate to multimedia

Update to 3.0.0:

• Add examples
• Expand ${CATEGORIES}, and move to correct category, multimedia/
• Update compiler to C++ 2017 in ${USES}
• Mark DOXYGEN broken because the build does not produce a required tag file
• port(clippy|fmt|lint) maintenance
• submitter becomes maintainer

Changelog: https://github.com/SFML/SFML/releases/tag/3.0.0

PR: 297879