ForemanModal was used for state management in Katello and other plugins (at least PRs). In Katello, it was replaced by a helper for handling those bulk states. As this is also helpful for other plugins (e.g. foreman_puppet), it makes sense to extract it to Foreman core.

Katello PR: https://github.com/Katello/katello/pull/11626
foreman_puppet PR: https://github.com/theforeman/foreman_puppet/pull/429