Add a test for citus_shards where table names have spaces

There was a bug reported for previous versions of Citus where
shard_size was returning NULL for tables with spaces in them. It works
fine on the main branch though, but I'm still adding a test for this to
the main branch because it seems a good test to have.

src/test/regress/citus_tests/run_test.py

@@ -148,6 +148,7 @@ def extra_tests(self):
         worker_count=6,
     ),
     "function_propagation": TestDeps("minimal_schedule"),
+    "citus_shards": TestDeps("minimal_schedule"),
     "grant_on_foreign_server_propagation": TestDeps("minimal_schedule"),
     "multi_mx_modifying_xacts": TestDeps(None, ["multi_mx_create_table"]),
     "multi_mx_router_planner": TestDeps(None, ["multi_mx_create_table"]),

src/test/regress/expected/citus_shards.out

@@ -0,0 +1,8 @@
+CREATE SCHEMA citus_shards;
+SET search_path TO citus_shards;
+SET citus.shard_count TO 4;
+SET citus.shard_replication_factor TO 1;
+SET citus.next_shard_id TO 99456900;
+-- add tests here
+SET client_min_messages TO WARNING;
+DROP SCHEMA citus_shards CASCADE;

src/test/regress/multi_1_schedule

@@ -53,6 +53,8 @@ test: multi_read_from_secondaries
 test: grant_on_database_propagation
 test: alter_database_propagation
 
+test: citus_shards
+
 # ----------
 # multi_citus_tools tests utility functions written for citus tools
 # ----------

src/test/regress/sql/citus_shards.sql

@@ -0,0 +1,16 @@
+CREATE SCHEMA citus_shards;
+SET search_path TO citus_shards;
+SET citus.shard_count TO 4;
+SET citus.shard_replication_factor TO 1;
+SET citus.next_shard_id TO 99456900;
+
+CREATE TABLE t1 (i int);
+SELECT create_distributed_table('t1', 'i');
+CREATE TABLE "t with space" (i int);
+SELECT create_distributed_table('"t with space"', 'i');
+INSERT INTO t1 SELECT generate_series(1, 100);
+INSERT INTO "t with space" SELECT generate_series(1, 1000);
+SELECT * FROM citus_shards;
+
+SET client_min_messages TO WARNING;
+DROP SCHEMA citus_shards CASCADE;