Clean up duplicate role and schema names in regression tests.

Since these names are global, using the same ones in different regression
tests creates a hazard of test failures if any two such scripts run
concurrently.  Let's establish a policy of not doing that.  In the cases
where a conflict existed, I chose to rename both sides: in principle one
script or the other could've been left in possession of the common name,
but that seems to just invite more trouble of the same sort.

There are a number of places where scripts are using names that seem
unduly generic, but in the absence of actual conflicts I left them alone.

In addition, fix insert.sql's use of "someone_else" as a role name.
That's a flat out violation of longstanding project policy, so back-patch
that change to v10 where the usage appeared.  The rest of this is just
future-proofing, as no two of these scripts are actually run concurrently
in the existing parallel_schedule.

Conflicts of schema-qualified names also exist, but will be dealt with
separately.

Discussion: https://postgr.es/m/4627.1521070268@sss.pgh.pa.us

Author: tglsfdc

src/test/regress/expected/insert.out

@@ -429,16 +429,16 @@ drop table mlparted5;
 -- appropriate key description (or none) in various situations
 create table key_desc (a int, b int) partition by list ((a+0));
 create table key_desc_1 partition of key_desc for values in (1) partition by range (b);
-create user someone_else;
-grant select (a) on key_desc_1 to someone_else;
-grant insert on key_desc to someone_else;
-set role someone_else;
+create user regress_insert_other_user;
+grant select (a) on key_desc_1 to regress_insert_other_user;
+grant insert on key_desc to regress_insert_other_user;
+set role regress_insert_other_user;
 -- no key description is shown
 insert into key_desc values (1, 1);
 ERROR:  no partition of relation "key_desc_1" found for row
 reset role;
-grant select (b) on key_desc_1 to someone_else;
-set role someone_else;
+grant select (b) on key_desc_1 to regress_insert_other_user;
+set role regress_insert_other_user;
 -- key description (b)=(1) is now shown
 insert into key_desc values (1, 1);
 ERROR:  no partition of relation "key_desc_1" found for row
@@ -447,9 +447,9 @@ DETAIL:  Partition key of the failing row contains (b) = (1).
 insert into key_desc values (2, 1);
 ERROR:  no partition of relation "key_desc" found for row
 reset role;
-revoke all on key_desc from someone_else;
-revoke all on key_desc_1 from someone_else;
-drop role someone_else;
+revoke all on key_desc from regress_insert_other_user;
+revoke all on key_desc_1 from regress_insert_other_user;
+drop role regress_insert_other_user;
 drop table key_desc, key_desc_1;
 -- test minvalue/maxvalue restrictions
 create table mcrparted (a int, b int, c int) partition by range (a, abs(b), c);

src/test/regress/sql/insert.sql

@@ -280,26 +280,26 @@ drop table mlparted5;
 create table key_desc (a int, b int) partition by list ((a+0));
 create table key_desc_1 partition of key_desc for values in (1) partition by range (b);
 
-create user someone_else;
-grant select (a) on key_desc_1 to someone_else;
-grant insert on key_desc to someone_else;
+create user regress_insert_other_user;
+grant select (a) on key_desc_1 to regress_insert_other_user;
+grant insert on key_desc to regress_insert_other_user;
 
-set role someone_else;
+set role regress_insert_other_user;
 -- no key description is shown
 insert into key_desc values (1, 1);
 
 reset role;
-grant select (b) on key_desc_1 to someone_else;
-set role someone_else;
+grant select (b) on key_desc_1 to regress_insert_other_user;
+set role regress_insert_other_user;
 -- key description (b)=(1) is now shown
 insert into key_desc values (1, 1);
 
 -- key description is not shown if key contains expression
 insert into key_desc values (2, 1);
 reset role;
-revoke all on key_desc from someone_else;
-revoke all on key_desc_1 from someone_else;
-drop role someone_else;
+revoke all on key_desc from regress_insert_other_user;
+revoke all on key_desc_1 from regress_insert_other_user;
+drop role regress_insert_other_user;
 drop table key_desc, key_desc_1;
 
 -- test minvalue/maxvalue restrictions