Native Giphy API integration

[DezzyTee]

Is your feature request related to a problem? Please describe.

At the moment you need to download a GIF and then reupload it to your Humhub site.

Describe the solution you'd like

Easy native integration of the Giphy API via the SDK.
You should be able to query a Giphy search and post a GIF from inside of the Humhub comment section, similar to how Facebook does it.

Describe alternatives you've considered

The alternative to just embed them isn't optimal but it doesn't matter since it doesn't work anyway.
I think Giphy removed oEmbed since they want people to use their SDK and API.

[AspHak]

I agree, would make it so much better than copying gif link to image location, or uploading. Makes it easier for more users.

[luke-]

Related: humhub/mail#405