fix: allow cast on types with underscores/numbers

e.g. select=oid_array::_int4

test/spec/fixtures/data.sql

@@ -762,3 +762,12 @@ INSERT INTO test.limited_delete_items_cpk VALUES (1, 'item-1'), (2, 'item-2'), (
 
 TRUNCATE TABLE test.limited_delete_items_no_pk CASCADE;
 INSERT INTO test.limited_delete_items_no_pk VALUES (1, 'item-1'), (2, 'item-2'), (3, 'item-3');
+
+TRUNCATE TABLE test.xmltest CASCADE;
+INSERT INTO test.xmltest VALUES
+(1, '<myxml>foo</myxml>'),
+(2, 'bar'),
+(3, '<foobar><baz/></foobar>');
+
+TRUNCATE TABLE test.oid_test CASCADE;
+INSERT INTO oid_test(id, oid_col, oid_array_col) VALUES (1, '12345', '{1,2,3,4,5}'::oid[]);

test/spec/fixtures/privileges.sql

@@ -179,6 +179,7 @@ GRANT ALL ON TABLE
     , limited_delete_items_cpk_view
     , limited_update_items_cpk_view
     , xmltest
+    , oid_test
 TO postgrest_test_anonymous;
 
 GRANT INSERT ON TABLE insertonly TO postgrest_test_anonymous;

test/spec/fixtures/schema.sql

@@ -2589,7 +2589,7 @@ CREATE TABLE test.xmltest (
     xml pg_catalog.xml NOT NULL
 );
 
-INSERT INTO test.xmltest VALUES
-(1, '<myxml>foo</myxml>'),
-(2, 'bar'),
-(3, '<foobar><baz/></foobar>');
+CREATE TABLE oid_test(
+  id int,
+  oid_col oid,
+  oid_array_col oid[]);