LR: Fix CSV generator to account for all rows

[sayan-das-in]

Liveramp considers the identifiers present in just the first row to compute CSV Headers, this PR fixes the CSV generation logic to consider all rows while generating CSV headers.

Test payload

[
  {
    audience_key: "aud001",
    delimiter: ",",
    filename: "test_file_name.csv",
    enable_batching: true,
  },
  {
    audience_key: "aud002",
    delimiter: ",",
    unhashed_identifier_data: {
      email: "[email protected]",
    },
    filename: "test_file_name.csv",
    enable_batching: true,
  },
  {
    audience_key: "aud003",
    delimiter: ",",
    unhashed_identifier_data: {
      email: "[email protected]",
      example_identifier: "example-id",
    },
    filename: "test_file_name.csv",
    enable_batching: true,
  },
];

Before the fix

After the fix

Testing

testing completed successfully via unit tests.

• Added unit tests for new functionality
• Tested end-to-end using the local server
• [Segmenters] Tested in the staging environment

[joe-ayoub-segment]

Hi @sayan-das-in should this need a Push when deployed?

[sayan-das-in]

Hi @joe-ayoub-segment this is an internal logic change and doesn't need a push.

[joe-ayoub-segment]

Hi @sayan-das-in this PR has been deployed