add click ID fields to Utm type for ad platform tracking

[arifraveendran]

Summary

• Adds 9 ad platform click ID fields (gclid, fbclid, msclkid, gbraid, wbraid, dclid, ttclid, li_fat_id, ScCid) to the Utm type
• Adds index signature [key: string]: string for future-proofing
• No logic changes — formUrl() already iterates all keys in the utm object

Related PRs

• joinditto/dma — passes click IDs via loadTimely()
• joinditto/timely-frontend#95 — receives click IDs in utmKeys

Test plan

• Build the plugin successfully
• Verify DMA can pass click IDs to the Timely iframe without TypeScript errors