Clicking on Youtube Embed redirect errors out

[rustynwac]

Describe the bug
When you try to watch an embedded YouTube video, it works but if you click on the button to watch on Youtube, you get an error

To Reproduce
Steps to reproduce the behavior:

1. Go to https://www.sawtoothavalanche.com/how-to-use-the-forecast
2. Start a vid
3. Click on the Youtube button within the vid (to 'Watch on Youtube')
4. See error

Expected behavior

Screenshots
https://www.loom.com/share/d4bed14b29994d6e8a8a8a94dbbca811

Environment details

Safari and Chrome from a Desktop.

Existential musings
What else you got for us?

[busbyk]

This seems to be due to the fact that we sandbox the GenericEmbed block in an iframe. So there are actually two nested iframes: ours and YouTube's.

We might be able to resolve this by setting additional attributes in our sandbox and allow attributes.