Lazy engine doesn't handle query params properly

[nightire]

I stumbled upon that the lazy engine cannot handle the query params very well.

For example, a host app mounted an engine as blog, so /blog will load this engine lazily. Then:

1. If we input /blog?foo=123 directly, BlogController.foo will be null, but it should be 123.
2. If we transition to /blog?foo=123 from the host app, then BlogController.foo will be 123.

Not sure if this is a bug or intentional.