Integrate proper logging framework

[LitschiW]

Replace all System.out.println with a proper logger such as log4j2.

e.g. by adding log4j-slf4j-impl

<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-slf4j-impl</artifactId>
    <version>2.20.0</version>
</dependency>

to the pom and adding a logger.

Also setup Lombok for convenience.