Change pgcrypto to use the new ResourceOwner mechanism.
This is a nice example of how extensions can now use ResourceOwners to
track extension-specific resource kinds
Reviewed-by: Peter Eisentraut, Andres Freund
Discussion: https://www.postgresql.org/message-id/
d746cead-a1ef-7efe-fb47-
933311e876a3%40iki.fi