bug#44895: Add Info-copy-permalink

[Drew Adams]

> In Gnus that is a human readable hyperlink (to the local Info manual,
> not to the HTML version at gnu.org).

Being able to obtain each kind of hyperlink
is useful: Info link and web link.  The use
cases are orthogonal.

FWIW, I use my `G' (`Info-goto-node-web') all
the time, to point users to a node from an
email or in some online forum.

I often also tell them how to get to the same
node from within Emacs.  But the two kinds of
access information are different.  Both are
useful.