Re: tablesync copy ignores publication actions

PSA v2 of the patch, based on all feedback received.

~~~

Main differences from v1:

* Rewording and more explanatory text.

* The examples were moved to the "Subscription" [1] page and also
extended to show some normal replication and row filter examples, from
[Amit].

* Added some text to CREATE PUBLICATION 'publish' param [2], from [Euler][Amit].

* Added some text to CREATE SUBSCRIPTION Notes [3], from [Shi-san].

* Added some text to the "Publication page" [4] to say the 'publish'
is only for DML operations.

* I changed the note in "Row Filter - Initial Data Synchronization"
[5] to be a warning because I felt users could be surprised to see
data exposed by the initial copy, which a DML operation would not
expose.

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[1] https://www.postgresql.org/docs/devel/logical-replication-subscription.html
[2] https://www.postgresql.org/docs/devel/sql-createpublication.html
[3] https://www.postgresql.org/docs/devel/sql-createsubscription.html
[4] https://www.postgresql.org/docs/devel/logical-replication-publication.html
[5] https://www.postgresql.org/docs/devel/logical-replication-row-filter.html#LOGICAL-REPLICATION-ROW-FILTER-INITIAL-DATA-SYNC

[Euler] https://www.postgresql.org/message-id/bd49c14d-7a01-4ae3-b424-8c49630fec57%40www.fastmail.com
[Amit] https://www.postgresql.org/message-id/CAA4eK1Lb5QpWCQU8qkELnX6t8z7JeVtGantmKptxkkpxnYnpHA%40mail.gmail.com
[Shi-san] https://www.postgresql.org/message-id/OSZPR01MB631026B8428422EAC1BFB8A4FDAA9%40OSZPR01MB6310.jpnprd01.prod.outlook.com

Kind Regards,
Peter Smith.
Fujitsu Australia