We previously had translateMediaToClientDBMediaInfo which gave us one ClientDBMediaInfo for each Media... but now the relationship between Media and "upload" is no longer 1:1.
translateMediaToClientDBMediaInfos replaces the existing function and returns an array with all of the ClientDBMediaInfos for a media message. By using this function in translateRawMessageInfoToClientDBMessageInfo we ensure that both the video and thumbnail are persisted in the media table of the SQLite "clientDB" database.