Fixed an Parquet check and consistency

[gmanolache]

Description of changes:

Generating a configuration failed for Parquet as it was expecting all uppercase, changed it everywhere to match the rest of the data formats as well.

Fixed an issue when copying the manifest that contained parquet files because Redshift was expecting the meta property content_length

Here are the cloudwatch logs I was getting:

  | 2020-11-15T17:38:14.824+01:00 | COPY my_test_table from 's3://lambda-redshift-loader-test/files/manifest-2020-11-15 16:38:14-6082' with credentials as 'aws_access_key_id=meyaccesskey;aws_secret_access_key=mykey' manifest format as PARQUET;
-- | -- | --
  | 2020-11-15T17:38:14.824+01:00 | commit;
  | 2020-11-15T17:38:16.200+01:00 | error:
  | 2020-11-15T17:38:16.200+01:00 | -----------------------------------------------
  | 2020-11-15T17:38:16.200+01:00 | error: File entry does not have 'meta' key.
  | 2020-11-15T17:38:16.200+01:00 | code: 15003
  | 2020-11-15T17:38:16.200+01:00 | context:
  | 2020-11-15T17:38:16.200+01:00 | query: 90820823
  | 2020-11-15T17:38:16.200+01:00 | location: spectrum_manifest.cpp:204
  | 2020-11-15T17:38:16.200+01:00 | process: padbmaster [pid=17049]

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