happy-families: Make sure we can accomodate keys that need to be hashed
PQ keys can quite long; we should make sure that the happy families proposal can accomodate cases where family-keys have truncated keys.
In particular, we should look at how we refer to keys vs key fingerprints, and we should make sure that the "client behavior" section defines what it means for an entry in family-keys
or family-cert
to "match".