Bugfix Enhancement

Keyword: Logging

Major

Systematic logging for Kafka
Kafka & TL-Sync swap log messages to own file

Detail

Update library log4j to version >= 2.16.0
Logging in KBDataProducerTask should cover error cases better
Get log output even without log viewer

Detail

Inconsistent logging: scheduler uses its own log file, but its tasks do not
Cyclic FileSystemProvider dependency in Log4J2
Unexpected order of backup log files with Log4j2
MaintenanceJspBase should write to the log first, then to the client, instead of the other way around.