Remove dependencies on supported_languages (central server) code

Depends on #1737, Fixes #1742 

Removing distributed server dependency on central-only code.  The central server changes (to provide a dubbed video map that doesn't require the mapping that's being removed here) will be done on the central server side shortly.

A similar (but separate) PR will be needed for `0.11.2`; will do once this one is in.