Planetary.link URLs are broken

[mplorentz]

When users try to share a message or profile in Planetary we give them a planetary.link URL. The Planetary.link URL has been down for some time and will be replaced by or updated to the new web viewer we are building.

What should we do with this links in the meantime? Maybe the share buttons should just copy the text of the post we are sharing, and for profiles we could just let users copy the profile ID? Maybe we should allow users to copy an SSB URI (#382) instead of an HTTP URL? Even when we get planetary.name online it doesn't make sense to let users copy a URL to it for any post, since most posts will not be visible there.