Generalize workflow for re-applying package curations

[fviernau]

Re-applying package currently works as follows

1. Drop all curations from the ORT result
2. Apply all curations found in the package curations directory

The workflow assumes that no other curation providers, besides the package configuration directory, are used.

Task:

• Find a way to see the effect of local configuration changes without loosing curations from other providers. (This is in large parts an ORT task likely)
• Note: Maybe the use case of using multiple curation directories, like "upstream ort-config" plus "private ort-config" will become important and should be supported as well.