Use Datawrapper API to get embed codes

[nmorduch]

Rather than requiring people enter the entire embed code into a Datawrapper embed Streamfield block, have them just enter the chart ID (which they do already enter, it just doesn't do anything) and use the Datawrapper API to grab the embed code on save. I think the best way to do this is to have checkboxes re whether to overwrite each thing, so that you're not required to have lots of things happen automatically

• Optionally overwrite embed code on save based on chart ID
  • Once this is working, we might want to just hide the embed code from the editor, since it really won't be necessary
• Get image via Datawrapper API (make sure to do this in a way where it's still possible to manually upload the image, since sometimes the image that's pulled automatically isn't right)
  • On save, if no fallback image, get fallback image
  • Ideally add a checkbox for: if checked, then on save, update image (update the image model rather than adding a new one)
• Add a checkbox for republishing the chart on save
• Ideally have some sort of note on save that makes sure you know chart info will be overwritten (in case you're editing something else and you didn't realize there were charts that would be messed with)