Remove log4j-appserver and log4j-jcl from 3.x

[ppkarwasz]

As discussed in this dev@logging thread, the log4j-appserver and log4j-jcl artifacts should be removed in 3.x:

• the functionality of log4j-jcl has been transfered to commons-logging itself (Add support for Log4j API and SLF4J commons-logging#177),
• the Jetty appender in log4j-appserver is no longer useful, since Jetty 9.x reached the end of community support (End of Community Support for Jetty 9.x - June 2022 jetty/jetty.project#7958),
• I have moved the Tomcat appender to my personal repo (Add Tomcat JULI Log implementation copernik-eu/log4j-tomcat#101). Remark that migrating it to the Tomcat project was discussed in this dev@tomcat thread).

[ppkarwasz]

Closed by #2257