Make link specifier handling in rend-spec-v3 more precise
Split off legacy/trac#26627.
We should specify that clients and services must not check untrusted link specifiers against the consensus:
https://gitweb.torproject.org/torspec.git/tree/rend-spec-v3.txt#n1338
https://gitweb.torproject.org/torspec.git/tree/rend-spec-v3.txt#n1705
Services should also copy unrecognized rend point link specifiers from the introduce cell to the rendezvous join cell.
We can copy the text from the service intro->rend spec:
https://gitweb.torproject.org/torspec.git/tree/rend-spec-v3.txt#n1705
To the the client desc->intro spec:
https://gitweb.torproject.org/torspec.git/tree/rend-spec-v3.txt#n1338
Thanks to catalyst for picking up on these missing parts of the spec.
Edit: fix line numbers
issue