Set ActiveSnapshot when logically replaying inserts

Input functions for the inserted tuples may require a snapshot, when
they are replayed by native logical replication.  An example is a domain
with a constraint using a SQL-language function, which prior to this
commit failed to apply on the subscriber side.

Reported-by: Mai Peng <maily.peng@webedia-group.com>
Co-authored-by: Minh-Quan TRAN <qtran@itscaro.me>
Co-authored-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/4EB4BD78-BFC3-4D04-B8DA-D53DF7160354@webedia-group.com
Discussion: https://postgr.es/m/153211336163.1404.11721804383024050689@wrigleys.postgresql.org