Ensure the backwards compatibility aliases are loaded

Ensure that if an application never references the old aliases that they
are still setup. Without this applications with typehints against the
old aliases can sometimes fail.

src/Http/Response.php

@@ -2425,3 +2425,6 @@ public function __debugInfo()
         ];
     }
 }
+
+// Ensure backwards compat alias exists.
+class_alias('Cake\Http\Response', 'Cake\Network\Response');

src/Http/ServerRequest.php

@@ -2129,3 +2129,6 @@ public function offsetUnset($name)
         unset($this->params[$name]);
     }
 }
+
+// Ensure backwards compat alias exists.
+class_alias('Cake\Http\ServerRequest', 'Cake\Network\Request');