feat: Add campaign click results view and CSV export (#2501)

[hariomop12]

Summary

This PR implements a feature to view and export campaign click results as requested in #2501.

Changes Introduced

• Created SQL campaign_results_view to join click data with subscriber and link details.
• Added API endpoint /api/campaigns/results/csv to export results as CSV.
• Registered Go query and model (CampaignResult) to support the above view.
• Added UI export button to trigger the endpoint.

Sample CSV Format

Campaign Name	Campaign ID	Email	Link ID	Link URL	Count

Testing

• Created sample campaign, subscriber, and link via SQL insert.
• Confirmed click tracking works.
• Verified CSV download with curl:

  curl -OJ http://localhost:9000/api/campaigns/results/csv

[hariomop12]

Hi sir 👋 Just wanted to confirm that I’ve tested the feature locally and ensured no existing behavior is broken.
Let me know if you need any changes — happy to update the PR. Thanks!

[knadh]

Hi @hariomop12. Could you please share a screenshot of the UI changes?

[kapil-collabtic]

@hariomop12 can you share please eagerly waiting for this update.

[mevinbabuc]

@hariomop12 Would love to see this happen

[github-actions]

This PR has been marked 'stale' after 90 days of inactivity. If there is no further activity, it will be closed in 7 days.