ForeignAPIRepo: Fetch thumb error from foreign repo

ForeignAPIRepo: Fetch thumb error from foreign repo

When the api of the foreign repo gives a thumb error, this is now
reported to the user.

This can produce an extra request to the api, when the language of the
user does not match the content language of the client. In that case an
extra request is used to get a localized error message.

Change-Id: I6bda81899d0f11a0091b973ab49fd8e0f976ee09