Add test to assess claim in SPR-10330

This commit verifies that JdbcTestUtils.readScript() properly handles
SQL comments prefixed by tab characters.

Issue: SPR-10330

spring-test/src/test/resources/org/springframework/test/jdbc/test-data-with-comments-and-leading-tabs.sql

@@ -0,0 +1,9 @@
+-- The next comment line starts with a tab.
+	-- x, y, z...
+
+insert into customer (id, name)
+values	(1, 'Sam Brannen');
+	-- This is also a comment with a leading tab.
+insert into orders(id, order_date, customer_id) values (1, '2013-06-08', 1);
+	 	-- This is also a comment with a leading tab, a space, and a tab.
+insert into orders(id, order_date, customer_id) values (2, '2013-06-08', 1);