Add support for MATERIALIZED keyword formatting

[matthiasmast]

A query without MATERIALIZED is formatted e.g. like this

WITH test_data AS
    (SELECT data1,
            data2,
            data3
     FROM test_table)
SELECT *
FROM test_data

after adding the MATERIALIZED keyword it is formatted like this

WITH test_data AS MATERIALIZED
    (SELECT data1, data2, data3
     FROM test_table)
SELECT *
FROM test_data

but it should be formatted like this

WITH test_data AS MATERIALIZED 
    (SELECT data1,
            data2,
            data3
     FROM test_table)
SELECT *
FROM test_data