Fixed local file partitioning file not found issue #976

[benamartin43]

Added code to create parent directories when partitioning is used. I found that the code to automatically do this seems to have been removed when the iceberg partitioning was added (b0c83ea). I have based my code on the previous code. Please let me know if I need to change the PR in any way.

I was able to reproduce #976 and verify the fix using the following query with the nexmark data source.

CREATE TABLE sink (
  window_start TIMESTAMP,
  total DOUBLE,
  bid_count BIGINT,
  name TEXT
) WITH (
  connector = 'filesystem',
  type = 'sink',
  path = 'file:////tmp/',
  format = 'parquet',
  'partitioning.time_pattern' = 'year=%Y/month=%m/day=%d/hour=%H/minute=%M'
);

INSERT INTO sink
SELECT 
    window.start as window_start,
    total,
    bid_count,
    name
FROM (
    SELECT 
        TUMBLE(INTERVAL '1 minute') as window,
        person.name as name,
        SUM(CAST(bid.price AS DOUBLE)) as total,
        COUNT(*) as bid_count
    FROM nexmark
    GROUP BY 
        TUMBLE(INTERVAL '1 minute'),
        person.name
);

[mwylde]

Apologies for the slow review and thanks for the fix!