Added logo for 'tnc' platform, added color for distribution bar in Re…

[RaginiAngarka]

Changes proposed ✍️

What

Added logo for platform = 'tnc'
Added fix for 'Cvent' platform is not showing in the 'Activities by platform' distribution bar in Reports

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🤖 Generated by Copilot at 8465690

We're adding colors to the charts of doom
We're creating files for the tnc integration
We're importing and exporting config objects
We're rocking the dashboard with our code innovation
Added logo platform = 'tnc'
https://github.com/CrowdDotDev/linux-foundation-support/issues/187

How

🤖 Generated by Copilot at 8465690

• Add chartColor property to cvent and lfx integration configs to customize chart appearance (link, link)
• Create new tnc integration config file with properties such as name, description, icon, chartColor, and apiUrl (link)
• Export tnc integration config object from a separate index file for easier import (link)
• Import and register tnc integration config in integrations-config.js file to make it available for use (link, link)

Checklist ✅

• Label appropriately with Feature, Improvement, or Bug.
• Add screehshots to the PR description for relevant FE changes
• New backend functionality has been unit-tested.
• API documentation has been updated (if necessary) (see docs on API documentation).
• Quality standards are met.