Remove links from tours for museum displays

[hyanwong]

When a tour is viewed in "museum display" mode (e.g. https://beta.onezoom.org/life_MDtouch/), we should make sure that the user can't follow URL links (I don't know if this is possible for videos, however). For example, the first stop on the "Cats" tour has an image which links out to wikipedia This would allow museum display users to escape the OneZoom sandbox.

There is a system implemented in the layout modules for checking whether we are in a mode which allows links to be followed: we should tie in to that properly.

[lentinj]

AFAIK the only links we have are for image copyright purposes, which wouldn't be accessible if we just got rid of the link. We could disable these easily enough, but that's not ideal.

Showing the content, link-stripped in a pop-up as we do with wikipedia tabs would be the right thing to do, but I'm not sure how easy that would be off the top of my head.

I guess eventually we'll have a similar problem with "window_text" containing links, they could be stripped but it might make the resultant text read weird---"click here to visit the EoL website" with no link.

[lentinj]

For now the tours mechanism is entirely hidden on a museum display, although with an appropriately crafted URL you could still activate a tour.

I think using javascript to extract a Credit Line for a wikimedia image, and ensuring we have a convention to extract credit lines out of our own pages, is the way forward.

If this is done, then we can add a mechanism to strip the links from museum display tour images.