Make protobuf a required dependency of drools-compiler because KieServices.newKieBuilder() doesn't work without it. => Remove all unneeded protobuf dependency verbosity from examples and other modules
pom code style: put groupId before artifactId + don't duplicate groupId if it's the same
Don't hardcode 6.0.0-SNAPSHOT, use ${project.version} instead.
pom code style: XML files use 2 spaces identation + groupId before artifactId
docs: typo
knowledge-api-legacy5-adapter: fix typo in directory name