Error when used on "Remote video" media

Problem/Motivation

Exception thrown when using on a "Remote video" media, as it tries to format assuming it is an image.

Steps to reproduce

- have media reference field that users can choose from "Image" or "Remote video" content (we need to allow a mix)
- use the "Responsive thumbnail" formatter
- add content with at least one "Remote video"
- view the content

Proposed resolution

Would be good to only apply the "Resposive thumbnail" settings to the "Image" media type.

But I suppose it would still need show the other formatter options for the other media types, so I'm not sure if this will be an easy fix.

Remaining tasks

User interface changes

API changes

Data model changes