The walkthrough render options

Every choice a walkthrough render accepts: the look templates, the voices, the orientations, the capture sizes (with the pixel size each records at), the length presets, the languages, the backgrounds, and the caption styles (each with the style block it is drawn from, so a client can show a faithful sample). The ids here are the ids renders.create and storyboards.create take. avatars is present and EMPTY while the presenter circle is switched off on this deployment; an avatarId is not a field those operations take then.