Allow to create package configurations from the UI #6385

For convenience, a user should be able to create package configurations from the UI. I'm esp. thinking about license findings curations, to deal with false-positives in detected licenses.

Note that (as this comment highlights) there is a both a semantic overlap of package configurations with package curations (as both can conclude licenses on different levels) and a mix of semantics (as both can do technical vs. legal stuff).

We should aim for a UX that makes these differences clearer, e.g. by configuring pathExcludes in a different view than licenseFindingCurations.