Publish does not cascade downward

[edschema]

Current Behavior
Publishing a container block in a library only publishes that container block and it's direct children. ie: publishing a section will publish the section and subsections it contains, but no units or content blocks contained

Desired Behavior
Publish should cascade all the way down, ie: if a section is published, all the subsections, units, and content blocks within that section should be published as well.

Notes
Ensure this fix addresses bug identified in #1977:

Create a subsection - add units - edit component within one of the units - navigate to browse page. The Subsection does not contain a draft status