Added in oEmbed metadata for single newsfeed pages

Closes engine#1854 (closed) Depends on engine!688 (merged)

To test

Go to an image or video, get the link from the header to visit it.

image

https://feat-oembed-front-4091.minds.io/api/v3/oembed?url=https%3A%2F%2Ffeat-oembed-front-4091.minds.io%2Fnewsfeed%2F1204458028565270543

video

https://feat-oembed-front-4091.minds.io/api/v3/oembed?url=https%3A%2F%2Ffeat-oembed-front-4091.minds.io%2Fnewsfeed%2F1170741574741528588

paywalled

• https://feat-oembed-front-4091.minds.io/newsfeed/1206271916436885516
• https://feat-oembed-front-4091.minds.io/api/v3/oembed?url=https%3A%2F%2Ffeat-oembed-front-4091.minds.io%2Fnewsfeed%2F1206271916436885516

For testing the front-end changes, open your DOM explorer and filter by "#oEmbed" - it should show the metatag when on videos and images.