As a developer I want to customize the code that Kogito generates.

PoC/MVP: allow to override codegen so that code is generated under src/main/java (or src/main/kogito-java or whatever). Codegen should not regenerate files under src/main.

Best results would require to separate generation of bare processes/rules/decisions (RuleUnit<T>, Process<T>, Decision<T>) from generation of their corresponding endpoints. This could be better addressed by a separate task.