In German law, the author and the copyright holder can be two seperate
legal entities and therefore also need to be treated separately.

Introduce a new copyright holder field that is now the primary source
for copyright holder information. Authors are still only used as
copyright holders if the `addAuthorsToCopyrights` option is enabled.

For now, all package manager implementations set empty copyright
holders. Filling the copyright holder field is left as an exercise for
future actions. Right now, the only way to add copyright holders is via
curations.

This change resolves oss-review-toolkit#4519.

Signed-off-by: Rainer Bieniek <extern.rainer.bieniek@porsche.de>

This helper CLI function is used by Porsche to solve the issue oss-review-toolkit#4364

The rationale behind this is that some projects at Porsche deliver individual
analyzer-results for each subproject in a large monorepo. The FOSS analyst needs
to see a condensed form of the individual dependency graphs across the project
monorepo. We solve this issue by merging all individual analyzer results into one.

Signed-off-by: Rainer Bieniek <extern.rainer.bieniek@porsche.de>