leaves - ui - implement embed / card provider

[xingh]

​Desc: in cases where wallabag can't get the data, use an embed provider, maybe put that s part of the initial scraping and store in a different area and then enhance it from our own DB instead of calling it from a third party

https://noembed.com/
https://github.com/leedo/noembed
http://urlembed.com/
https://www.quora.com/What-are-the-best-alternatives-to-Embed-ly

Acceptance Criteria: TBC

[xingh]

https://github.com/nicopace/noembed-docker

Noembed available as docker

[xingh]

https://oembed.com/