Add a test for GrapgQL (#10156)

## Problem
We currently don't run the tests shipped with `pg_graphql`.
## Summary of changes
The tests for `pg_graphql` are added.

docker-compose/ext-src/pg_graphql-src/neon-test.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+set -ex
+cd "$(dirname "${0}")"
+dropdb --if-exists contrib_regression
+createdb contrib_regression
+PGXS="$(dirname "$(pg_config --pgxs)" )"
+REGRESS="${PGXS}/../test/regress/pg_regress"
+TESTDIR="test"
+TESTS=$(ls "${TESTDIR}/sql" | sort )
+TESTS=${TESTS//\.sql/}
+psql -v ON_ERROR_STOP=1 -f test/fixtures.sql -d contrib_regression
+${REGRESS} --use-existing --dbname=contrib_regression --inputdir=${TESTDIR} ${TESTS}
+