[pg15] test: fully port regress yb_pg_select

Summary:
Fully port regress test select to yb_pg_select.  Make use of
yb_use_hash_splitting_by_default=false and compute_query_id=regress, now
set by default for ported tests.  Of particular note is that some YB
bitmap table scans output rows in a different order from upstream PG.  I
am not aware of the cause, but I assume it has to do with how YB's
bitmap scan internals are different.

Add new yb_dep_int8_tbl for support.

Test Plan:
On Almalinux 8:

    #!/usr/bin/env bash
    set -eu
    ./yb_build.sh fastdebug --gcc11
    yes "$(grep 'PgSelect$' pg15_tests/passing_tests.tsv)" | head -50 | pg15_tests/run_tests.sh

Depends on D36352
Jenkins: rebase: pg15, test regex: TestPgRegressPgSelect

Reviewers: aagrawal, fizaa, tfoucher

Reviewed By: aagrawal

Subscribers: yql

Differential Revision: https://phorge.dev.yugabyte.com/D36354

java/yb-pgsql/src/test/java/org/yb/pgsql/TestPgRegressPgSelect.java

@@ -20,7 +20,7 @@
  * Runs the pg_regress test suite on YB code.
  */
 @RunWith(value=YBTestRunner.class)
-public class TestPgRegressPgSelect extends BasePgRegressTest {
+public class TestPgRegressPgSelect extends BasePgRegressTestPorted {
  @Override
  public int getTestMethodTimeoutSec() {
  return 600;

src/postgres/src/test/regress/expected/yb_dep_int8_tbl.out

@@ -0,0 +1,19 @@
+--
+-- A collection of queries to build the int8_tbl table.
+--
+-- The queries are taken from the relevant dependency files. Since it is
+-- faster to run this rather than each file itself (e.g. dependency chain
+-- test_setup, create_index), prefer using this.
+--
+--
+-- test_setup
+--
+CREATE TABLE INT8_TBL(q1 int8, q2 int8);
+INSERT INTO INT8_TBL VALUES
+ (' 123 ',' 456'),
+ ('123 ','4567890123456789'),
+ ('4567890123456789','123'),
+ (+4567890123456789,'4567890123456789'),
+ ('+4567890123456789','-4567890123456789');
+VACUUM INT8_TBL;
+NOTICE: VACUUM is a no-op statement since YugabyteDB performs garbage collection of dead tuples automatically