Support configurable frame ancestors for embeds about lookbook HOT 2 OPEN

Hey @aduth, thanks for this and many apologies for taking so long to reply.

I have to say my knowledge of CSPs is still pretty limited (despite your help in #202) but what you are suggesting makes total sense.

My gut reaction is to go down the preview_embeds.frame_ancestors config option route as I still feel that keeping parity with the way that ViewComponent disables the CSP is probably still preferable. I'm also a little nervous about adding more complex policy configuration code when I don't feel like I have a lot of expertise in this area.

I'm pretty short of time for working on Lookbook at the moment but I'll try to have a proper think about this as soon as I can. As the config option route is probably simpler I may see if I can give that a go - I'll let you know once I have any code ready so you can take a look at it and see if it will work for you.

from lookbook.

Hi @allmarkedup, totally understand if you don't have the bandwidth for this at the moment! Fortunately our workaround is serving us just fine for the time being, but we'll look forward to this functionality being supported out of the box. Happy to review or provide feedback for any changes or ideas you come up with.

from lookbook.