fix(enrichment_tables): Fix csv file enrichment tables without header dropping the first row

[B-Schmidt]

Summary

• Currently, file enrichment tables loaded from a csv file without headers loose the first row of data in that file
• Fix this by keeping the first data row in a separate variable and then chaining it into the remaining data rows when parsing columns
• Provide unit tests for loading a csv file both with and without header row

Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

How did you test this PR?

• Unit tests are provided in the PR
• Create data.csv

a,1
b,2

• Create vector.yaml

enrichment_tables:
  data:
    type: file
    file:
      encoding:
        type: csv
        include_headers: false
      path: ./data.csv

sources:
  in:
    type: stdin

transforms:
  remap:
    inputs: [in]
    type: remap
    source: |
      .row = get_enrichment_table_record("data", {"0": .message}) ?? null
      . = {"message": .message, "row": .row}

sinks:
  out:
    type: console
    inputs: [remap]
    encoding:
      codec: json

• Run vector -c vector.yaml providing the following input:

a
b
c

• Expected output:

{"message": "a", "row": {"0": "a", "1": "1"}}
{"message": "b", "row": {"0": "b", "1": "2"}}
{"message": "c", "row": null}

Does this PR include user facing changes?

• Yes. Please add a changelog fragment based on our guidelines.
• No. A maintainer will apply the "no-changelog" label to this PR.

Checklist

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References