pgsql: Rename the conflict types for the origin differ cases.

Rename the conflict types for the origin differ cases.

The conflict types 'update_differ' and 'delete_differ' indicate that a row
to be modified was previously altered by another origin. Rename those to
'update_origin_differs' and 'delete_origin_differs' to clarify their
meaning.

Author: Hou Zhijie
Reviewed-by: Shveta Malik, Peter Smith
Discussion: https://postgr.es/m/CAA4eK1+HEKwG_UYt4Zvwh5o_HoCKCjEGesRjJX38xAH3OxuuYA@mail.gmail.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/640178c92e3f6c74d275369b291b507834f1309e

Modified Files
--------------
doc/src/sgml/logical-replication.sgml      |  6 +++---
src/backend/replication/logical/conflict.c | 12 ++++++------
src/backend/replication/logical/worker.c   |  6 +++---
src/include/replication/conflict.h         |  4 ++--
src/test/subscription/t/013_partition.pl   |  2 +-
src/test/subscription/t/030_origin.pl      |  4 ++--
6 files changed, 17 insertions(+), 17 deletions(-)