databases/mysql-connector-j: Renamed and updated to 8.1.0

Starting on 8.0.31, upstream has renamed the port to mysql-connector-j
and the groupId and artifactId has changed to comply with proper naming
guidelines. Please read the changelog for more details.

Changes: https://dev.mysql.com/doc/relnotes/connector-j/8.1/en/news-8-1-0.html