Extract API v1 into a plugin
As APIv1 gets older, its discouraged from using. I would suggest we extract it from Core to a plugin initially before officially dropping support for it.
Fixes #11389 - Remove API v1
API v1 has been deprecated since Foreman 1.9 - over 2 years ago.
This is more then enough time for anyone needing to migrate to v2.
Even though the original issue requests extraction to a plugin, I do not
see any point in investing the time and effort to maintain a long