refactor: use logger instead of System.out.println

[soloturn]

would it be acceptable to you to use logger instead of system out in these cases?

[BenjaminAmos]

The logger changes seem fine to me. I will leave the LOGGER vs logger bit for others to decide upon.

I am a bit more concerned about the changes to the tools in the engine-tests/src/test/java/org/terasology/documentation folder. I suspect that these tools may have been intentionally not using a logging framework.

[BenjaminAmos]

The ApiScraper and ApiComparator tools were introduced in #3253. As far as I can tell, they were never used and I am unsure about how to test them directly. The output appears to be intended as more human readable than machine readable, so the logger changes may not be significantly detrimental here. Either way, merging is is unlikely to break anything, since this code appears to be unused.

The rest of the changes raise no concerns for me.

I am approving this but would still prefer a second opinion before merging.