Client side, when a descriptor is finally fetched and stored in the cache, we
then go over all pending SOCKS request for that descriptor. If it turns out
that the intro points are unusable, we close the first SOCKS request but not
the others for the same .onion.

This commit makes it that we'll close all SOCKS requests so we don't let
hanging the other ones.

It also fixes another bug which is having a SOCKS connection in RENDDESC_WAIT
state but with a descriptor in the cache. At some point, tor will expire the
intro failure cache which will make that descriptor usable again. When
retrying all SOCKS connection (retry_all_socks_conn_waiting_for_desc()), we
won't end up in the code path where we have already the descriptor for a
pending request causing a BUG().

Bottom line is that we should never have pending requests (waiting for a
descriptor) with that descriptor in the cache (even if unusable).

Fixees #27410

.

Signed-off-by: David Goulet <dgoulet@torproject.org>