Package license data structure: Improve tracing of license detection in package manifests

[pombredanne]

There is little to no logging in place as well as no intermediate results and it is therefore hard to understand how a package declared_license has been detected in a license_expression. We should potentially keep all the same intermediate results as we have in regular license detection as a diagnostic option, and while this may seem verbose this would be essential to track issues.

[AyanSinhaMahapatra]

This was added with the following PRs:

• Combine license matches in new LicenseDetection #2961
• More License Detection changes #3154
• Improve License Detection reporting #3286
  We now have the entire license detection objects with the matches (with file origin info) for detections in package manifests. so this is completely traceable. Closing!