Integrate Log4j with Jakarta EE

[jo-elimu]

After upgrading to Jetty 11, the Log4j logging stopped detecting the content_language attribute in log4j_PROD.xml, and outputs the logs to 'lang-${web:attr.content_language}' instead:

.elimu-ai]# ls
 deploy-webapp.sh  'lang-${web:attr.content_language}'   lang-ENG   lang-HIN   lang-TGL

├── lang-${web:attr.content_language}
│   └── logs
│       └── webapp.log

Seems related to the Jakarta name change.

https://logging.apache.org/log4j/2.x/jakarta.html