Add -Cn/--csv-no-header option to rdump

[yunzheng]

This allows you to dump the fields as CSV but without the row header.

Also fixes issue that in some cases the selected fields were not propagated to the adapter.

[Copilot]

Pull Request Overview

This PR introduces a new "--csv-no-header" option to the rdump tool, allowing users to output CSV files without a header and fixes a regression where the selected fields were not correctly propagated to the adapter.

• Adds the "csv-no-header" mode option and corresponding alias in the argument parser.
• Updates the CSV adapter to conditionally write the header based on the new parameter.
• Introduces regression tests to verify that selected fields are properly handled for both modes.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
tests/test_regression.py	Adds regression tests to verify selected fields propagation and CSV header behavior.
flow/record/tools/rdump.py	Updates argument parsing and URI construction to support the new csv-no-header mode.
flow/record/adapter/csvfile.py	Enhances the CSV adapter to conditionally write the header based on the new header parameter.

[codecov]

Codecov Report

Attention: Patch coverage is 93.10345% with 2 lines in your changes missing coverage. Please review.

Project coverage is 82.90%. Comparing base (1476f7a) to head (0c2132b).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
flow/record/adapter/elastic.py	66.66%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #170      +/-   ##
==========================================
+ Coverage   82.82%   82.90%   +0.07%     
==========================================
  Files          34       34              
  Lines        3576     3592      +16     
==========================================
+ Hits         2962     2978      +16     
  Misses        614      614              

Flag	Coverage Δ
unittests	82.90% <93.10%> (+0.07%)	⬆️

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