Configure Webhook Infrastructure for escrow_transactions Event Triggers

Description

This PR implements a comprehensive webhook infrastructure for handling escrow_transactions event triggers. The implementation includes proper endpoint configuration, retry mechanisms, authentication, error handling, and logging systems.

Changes Made

• Configured Hasura event trigger for escrow_transactions with proper retry policy
• Implemented webhook service with Express.js for handling event triggers
• Set up authentication middleware using webhook secrets
• Implemented idempotency checking to prevent duplicate processing
• Added comprehensive error handling and logging
• Created monitoring service for tracking webhook health and failures
• Implemented alerting system for persistent webhook failures
• Added database migrations for tracking processed events
• Configured rate limiting to prevent API abuse

Technical Details

• Retry Policy: 5 retries with exponential backoff, 15-second intervals, 60-second timeout
• Authentication: Token-based authentication using Authorization header
• Idempotency: Using X-Idempotency-Key header and database tracking
• Logging: Structured logging with Winston, separate error logs
• Monitoring: Tracks webhook health, generates reports, detects stalled webhooks
• Alerting: Email notifications for persistent failures

Closes #98