FORGE-879 RestPlugin allows choosing the injected persistence unit.

If multiple persistence units are detected in the persistence descriptor, then the plugin will prompt on which one needs to be used for the injected persistence context. If only one is found, then it would be used for the injected persistence context.
Revert "FORGE-863: Maven mirror settings are now being used"

This reverts commit 832cad6e45ab25f4e3be23acddb32b46bb8297c3.