Hero images for custom content types when machine name is too long

This issue is created on Github: https://github.com/goalgorilla/open_social/issues/726

Problem

If you use a custom content type (not provided by Open Social) and happens to have a long name, the validation above will fail because machine names can only be 26 characters long.

Solution

In order to at least have the possibility of having an image set, new code needs to load an image field as hero, as long as it has the word "image" on its field name and it is an image field.