fix: bug when Null Filtering on embedded resources

When doing Null Filtering, the to-one embed resources were not included if they had a NULL value in any of the selected fields.

test/spec/fixtures/data.sql

@@ -853,3 +853,8 @@ INSERT INTO datarep_next_two_todos VALUES (2, 1, 3, 'do these first');
 TRUNCATE TABLE bitchar_with_length CASCADE;
 INSERT INTO bitchar_with_length(bit, char) VALUES ('00000', 'aaaaa');
 INSERT INTO bitchar_with_length(bit, char) VALUES ('11111', 'bbbbb');
+
+TRUNCATE TABLE table_a CASCADE;
+INSERT INTO table_a(id, name) VALUES (1, 'Not null 1'), (2, null), (3, 'Not null 2');
+TRUNCATE TABLE table_b CASCADE;
+INSERT INTO table_b(table_a_id, name) VALUES (1, 'Test 1'), (2, 'Test 2'), (null, 'Test 3');

test/spec/fixtures/schema.sql

@@ -3437,3 +3437,13 @@ begin
       message = '{"code":"123","message":"ABC","details":"DEF"}';
 end
 $$;
+
+create table table_a (
+  id int primary key,
+  name text
+);
+
+create table table_b (
+  table_a_id int references table_a(id),
+  name text
+);