Fetches the explicitly-set related-media ("discover more") customizations
(which videos to recommend, when to show them, label and button text) for
the video.

Requires api token with one of the following permissions

Read all folder and media data

Tokens with the "Act with a team member's permissions" permission
(all:delegate_to_contact_permissions scope) can also be used. Requests
made with such a token are authorized using the permissions of the
contact assigned to the token.

An expiring access token
created with the all:delegate_to_contact_permissions scope and an
authorization for this media can also be used; any permission granted on
the media allows reading its customizations.