feat: implement push webhook service

[DavidAmunga]

Description

This PR introduces a new webhook service that allows users to send statement transaction data to external webhook endpoints for reconciliation and integration with external systems.

Changes

New Features

• Webhook Service (src/services/webhookService.ts):

  • New service for sending transaction data as JSON to any HTTP/HTTPS webhook endpoint
  • URL validation and protocol enforcement
  • Comprehensive error handling with user-friendly messages
  • Response body capture and display (both JSON and text)
  • Network error detection and CORS error handling

  Screenshot(s)

Use Cases

• Integration with accounting systems
• Automated transaction reconciliation
• Real-time transaction syncing with external databases
• Custom webhook integrations for payment processors

Technical Details

• Uses the existing JsonService for consistent data formatting
• Respects all export options (filters, sorting, etc.) when sending data
• POST request with Content-Type: application/json
• Handles both JSON and plain text responses
• Validates URLs and restricts to HTTP/HTTPS protocols only

Testing

Tested with local webhook endpoints and verified:

• Successful data transmission with 2xx responses
• Error handling for invalid URLs
• Network error detection
• Response body display (JSON and text)
• Loading states and user feedback