copy public URL on anchor context

[djdv]

Unfortunately, I don't know when this stopped working, or if it's actually intended to work this way.
But at some point previously, I could right-click anchors and copy their specific public url.
Now, when I do the same, it copies the public url to the current path, without the anchor's target.

e.g.
This

Should put
http://ipfs.io/ipfs/QmWn4vJepGcAEmT36FDL6ca1RxSXiuca9Ew8pb7RZGKbq4/symlink-tree.tar.xz
on the clipboard, but I end up with just
http://ipfs.io/ipfs/QmWn4vJepGcAEmT36FDL6ca1RxSXiuca9Ew8pb7RZGKbq4

Edit:
For reference, I'm getting this on Firefox and Vivaldi, with the latest stable and beta.

[lidel]

Ah, yes, we recently noticed context actions use shady heuristic that does not work for all use cases :)
Fixing one thing broke the other.

I'm trying to deliver what you want and a little bit more in this PR:
#585 (comment) ← would appreciate some feedback