Adds functional tests for new mysql_user privs (#48403)

Adds tests for FUNCTION and PROCEDURE privs

test/integration/targets/mysql_user/files/create-function.sql

@@ -0,0 +1,8 @@
+USE foo;
+DELIMITER ;;
+CREATE FUNCTION `function` () RETURNS tinyint(4)
+BEGIN
+  DECLARE NAME_FOUND tinyint DEFAULT 0;
+  RETURN NAME_FOUND;
+END;;
+DELIMITER ;