Remove the package_forwarding license feature and move package forwarding settings to Core

Summary

Currently, there is a license feature called package_forwarding that gates application settings controlling the package forwarding (npm, pypi).

The issue is that the API endpoints directly uses the application settings without checking the License. So the API endpoints use a feature from EE as if it was in Core.

Improvements

As discussed with the PM of package:

• remove the package_forwarding license feature
• move the application settings views to Core
• move the application settings entities to Core
• Update the related documentation

Risks

Package request forward are tested at the API level. Those tests reduce the risk level.

Involved components

• npm package endpoints
• pypi package endpoints