Align to GroovyDoc annotation

[pauxus]

In preparation of the Groovy 2 sunsetting.

• decide whether to include /** in apt output -> getDocComment removes it, currently we remove it as well, Groovy Runtime Doc retains ist
• AnnoDoc Utils should consider GroovyDoc Annotation in addition to AnnoDoc and Properties
• InlineJavadocs should short circuit if runtime Groovydoc is enabled
  • Actually, GroovyDoc is only generated if the comment starts with an @, so we might need do that anyway
  • Perhaps the @ should be explicitly included in the generated annotation
• InlineJavadocs should fail if Groovy 3+ and ast groovydoc is not enabled
  • This check should be embeddable in other AST Transformation classes
• AnnoDoc Utils should create Groovydoc annotations if using Groovy 3
• Generator should honor both AnnoDoc and GroovyDoc
• Generator Part should be optional (can IDEs handle Groocydoc annotations)