test: upserts with case sensitive table and sequence name (#4131)

Closes #3712.

test/spec/fixtures/data.sql

@@ -946,6 +946,9 @@ INSERT INTO surr_serial_upsert(name, extra) VALUES ('value', 'existing value');
 TRUNCATE TABLE surr_gen_default_upsert CASCADE;
 INSERT INTO surr_gen_default_upsert(name, extra) VALUES ('value', 'existing value');
 
+TRUNCATE TABLE "Surr_Gen_Default_Upsert" CASCADE;
+INSERT INTO "Surr_Gen_Default_Upsert"(name, extra) VALUES ('value cs', 'existing value cs');
+
 TRUNCATE TABLE tsearch_to_tsvector CASCADE;
 INSERT INTO tsearch_to_tsvector(text_search) VALUES ('It''s kind of fun to do the impossible');
 INSERT INTO tsearch_to_tsvector(text_search) VALUES ('But also fun to do what is possible');

test/spec/fixtures/privileges.sql

@@ -41,6 +41,7 @@ GRANT USAGE ON SEQUENCE
     , leak_id_seq
     , surr_serial_upsert_id_seq
     , surr_gen_default_upsert_id_seq
+    , "Surr_Gen_Default_Upsert_id_seq"
 TO postgrest_test_anonymous;
 
 GRANT USAGE ON SEQUENCE channels_id_seq TO postgrest_test_anonymous;

test/spec/fixtures/schema.sql

@@ -3750,6 +3750,13 @@ create table surr_gen_default_upsert (
   extra text
 );
 
+-- test for case-sensitive table name and sequence name, see #3712
+create table "Surr_Gen_Default_Upsert" (
+  id int generated by default as identity primary key,
+  name text,
+  extra text
+);
+
 create table tsearch_to_tsvector (
   text_search text,
   jsonb_search jsonb