Include replication origins in SQL functions for commit timestamp

This includes two changes:
- Addition of a new function pg_xact_commit_timestamp_origin() able, for
a given transaction ID, to return the commit timestamp and replication
origin of this transaction.  An equivalent function existed in
pglogical.
- Addition of the replication origin to pg_last_committed_xact().

The commit timestamp manager includes already APIs able to return the
replication origin of a transaction on top of its commit timestamp, but
the code paths for replication origins were never stressed as those
functions have never looked for a replication origin, and the SQL
functions available have never included this information since their
introduction in 73c986a.

While on it, refactor a test of modules/commit_ts/ to use tstzrange() to
check that a transaction timestamp is within the wanted range, making
the test a bit easier to read.

Bump catalog version.

Author: Movead Li
Reviewed-by: Madan Kumar, Michael Paquier
Discussion: https://postgr.es/m/2020051116430836450630@highgo.ca

src/test/modules/commit_ts/expected/commit_timestamp.out

@@ -39,9 +39,94 @@ SELECT pg_xact_commit_timestamp('2'::xid);
  
 (1 row)
 
-SELECT x.xid::text::bigint > 0, x.timestamp > '-infinity'::timestamptz, x.timestamp <= now() FROM pg_last_committed_xact() x;
- ?column? | ?column? | ?column? 
-----------+----------+----------
- t        | t        | t
+SELECT x.xid::text::bigint > 0 as xid_valid,
+    x.timestamp <@ tstzrange('-infinity'::timestamptz, now()) AS ts_in_range,
+    roident != 0 AS valid_roident
+  FROM pg_last_committed_xact() x;
+ xid_valid | ts_in_range | valid_roident 
+-----------+-------------+---------------
+ t         | t           | f
+(1 row)
+
+-- Test non-normal transaction ids.
+SELECT * FROM pg_xact_commit_timestamp_origin(NULL); -- ok, NULL
+ timestamp | roident 
+-----------+---------
+           |        
+(1 row)
+
+SELECT * FROM pg_xact_commit_timestamp_origin('0'::xid); -- error
+ERROR:  cannot retrieve commit timestamp for transaction 0
+SELECT * FROM pg_xact_commit_timestamp_origin('1'::xid); -- ok, NULL
+ timestamp | roident 
+-----------+---------
+           |        
+(1 row)
+
+SELECT * FROM pg_xact_commit_timestamp_origin('2'::xid); -- ok, NULL
+ timestamp | roident 
+-----------+---------
+           |        
+(1 row)
+
+-- Test transaction without replication origin
+SELECT txid_current() as txid_no_origin \gset
+SELECT x.timestamp <@ tstzrange('-infinity'::timestamptz, now()) AS ts_in_range,
+       roident != 0 AS valid_roident
+  FROM pg_last_committed_xact() x;
+ ts_in_range | valid_roident 
+-------------+---------------
+ t           | f
+(1 row)
+
+SELECT x.timestamp <@ tstzrange('-infinity'::timestamptz, now()) AS ts_in_range,
+       roident != 0 AS valid_roident
+  FROM pg_xact_commit_timestamp_origin(:'txid_no_origin') x;
+ ts_in_range | valid_roident 
+-------------+---------------
+ t           | f
+(1 row)
+
+-- Test transaction with replication origin
+SELECT pg_replication_origin_create('test_commit_ts: get_origin') != 0
+  AS valid_roident;
+ valid_roident 
+---------------
+ t
+(1 row)
+
+SELECT pg_replication_origin_session_setup('test_commit_ts: get_origin');
+ pg_replication_origin_session_setup 
+-------------------------------------
+ 
+(1 row)
+
+SELECT txid_current() as txid_with_origin \gset
+SELECT x.timestamp <@ tstzrange('-infinity'::timestamptz, now()) AS ts_in_range, r.roname
+  FROM pg_last_committed_xact() x, pg_replication_origin r
+  WHERE r.roident = x.roident;
+ ts_in_range |           roname           
+-------------+----------------------------
+ t           | test_commit_ts: get_origin
+(1 row)
+
+SELECT x.timestamp <@ tstzrange('-infinity'::timestamptz, now()) AS ts_in_range, r.roname
+  FROM pg_xact_commit_timestamp_origin(:'txid_with_origin') x, pg_replication_origin r
+  WHERE r.roident = x.roident;
+ ts_in_range |           roname           
+-------------+----------------------------
+ t           | test_commit_ts: get_origin
+(1 row)
+
+SELECT pg_replication_origin_session_reset();
+ pg_replication_origin_session_reset 
+-------------------------------------
+ 
+(1 row)
+
+SELECT pg_replication_origin_drop('test_commit_ts: get_origin');
+ pg_replication_origin_drop 
+----------------------------
+ 
 (1 row)