refactor: use DTO and terminate middleware for better performance

- Add PageviewData readonly DTO class for type safety
- Update AnalyticsClient to accept PageviewData instead of array
- Move analytics sending to terminate() method (runs after response sent)
- Update all tests for new DTO pattern

tests/TestCase.php

@@ -21,7 +21,7 @@ class TestCase extends Orchestra
 
     public function getEnvironmentSetUp($app)
     {
-        config()->set('mattitja-analytics.site_key', 'test-site-key');
+        config()->set('mattitja-analytics.site_key', 'testsiteky');
         config()->set('mattitja-analytics.enabled', true);
     }
 }