Remove unused form and enhance wash certificate handling

The `book_interior_wash_f` form was removed due to redundancy. Added functionality to handle wash certificate generation, including safety seal and operator data, and added a new form `complete_booking_f` to finalize bookings without certificates. Adjustments were made to several related components to ensure seamless integration.

services/nginx/app/traits/route_t.php

@@ -48,6 +48,15 @@ trait route_t
         return true;
     }
 
+    public function requireSameLength(mixed $arg1, mixed $arg2): bool
+    {
+        global $response;
+        if (strlen($arg1) !== strlen($arg2)) {
+            $response->error('Invalid length. Expected: ' . strlen($arg2) . ' Got: ' . strlen($arg1), 400);
+        }
+        return true;
+    }
+
     /**
      * Require parameter to be one of the given types
      * @param mixed $value The value to check