Permalink does not display after creating and saving a new Lesson

[brianhogg]

Reproduction Steps

1. In the course builder add a new lesson
2. Save Changes

Expected Behavior

Permalink for the lesson appears, and the "Open WordPress Lesson Editor" little icon in the top-right works

Actual Behavior

Permalink does not display

Related to http://github.com/gocodebox/lifterlms/issues/3030 and if we get the data from the back-end, this PR points in the right direction for the changes needed #2663

[brianhogg]

We could use the WP REST API or our REST API to grab the permalink via the post ID