[3.15] Query Params "Aliasing" Broken

As [discussed in the guides](https://guides.emberjs.com/release/routing/query-params/#toc_map-a-controllers-property-to-a-different-query-param-key) one can map a query parameter to a different value on their controller. This appears to be broken in Ember 3.15.

Reproduction app: https://github.com/jherdman/query-params-sadness

* **Second commit "Aliasing: Broken"**. Click the links, note that the query parameter does not change. Setting the query parameter `p` manually does not work either.
* **Third commit: "Work Around"**. Current work around I'm using, though this does not handle default values at all.