Webhook payloads checked against live events

We sent real Review and Loyalty events to a test endpoint and compared each payload with the examples on Topics.

Corrected:

• Tier Status Changed: vip_stats_needed_next and vip_stats_needed_maintain use points_needed, amount_cents_needed, purchases_needed, referrals_needed and campaigns_needed.
• review_create and review_updated include creation_request_id and rejection_reason.
• Tier Earned includes tier_change_type. Points Changed includes related_order_ids.
• Tier Lost, Loyalty Opt Out and Customer Anniversary Captured now show real payloads. Tier Lost also fires when a customer opts out.

New: Webhook request headers lists the headers sent with every event. Review events have no topic field, so read the event name from X-Yotpo-Webhooks-Event-Type.