Update maven configuration to use new repository layout

We are moving away from the nexus2 repository layout and need to implement the nexus3 layout.

For the time being we have the following proxy mappings in place to bridge the gap.
We will remove these mappings per November 1, so make sure to update you config beforehand.

EDIT: The table has been moved over to the Confluence page to have a single source of truth.

Make sure to update both your local settings.xml as well as entries in your projects pom.xml. (repositories & distribution management)