4.x: Use Helidon copyright module for generated code

[tomas-langer]

This task can be split between multiple developeres, please mark which module(s) you plan to work on, so others can work in parallel (if needed).

(see common/processor) for all Helidon modules that generate code (this will add proper Helidon copyright header to generated types that are part of our APIs)
Example of usages: builder/tests/common-types

Just add the following to annotation processor paths that already contains helidon-builder-processor or helidon-pico-processor, or helidon-pico-configdriven-processor

<path>
    <groupId>io.helidon.common.processor</groupId>
    <artifactId>helidon-common-processor-helidon-copyright</artifactId>
    <version>${helidon.version}</version>
</path>