feat: wait for query string

[Barbapapazes]

Hello 👋,

There is an assert called assertQueryStringHas but nothing to wait for a specific query string.

Actually, I have an input that will change the URL query string before showing the new data and having a way to wait for a change in the query string could be very useful.

[taylorotwell]

Thanks for your pull request to Laravel!

Unfortunately, I'm going to delay merging this code for now. To preserve our ability to adequately maintain the framework, we need to be very careful regarding the amount of code we include.

If applicable, please consider releasing your code as a package so that the community can still take advantage of your contributions!

[taylorotwell]

It feels like we should re-use or be consistent with how we pull / inspect the query string across these methods.