standardize property name of HTTP Kernel in Middleware classes

@jvbrian You've made a fork and it says there's a commit you've made, but I don't see anything on the feature branch?

I have created the patch please review it

You seem to have replaced $kernel wit $http_kernel everywhere, not just in the classes concerned in this issue, and also lots of places where it's actually the DrupalKernel!

This issue is only about middleware classes.

Also, please can you make a MR rather than a patch?

@joachim, I've created a Merge Request (MR) for your review.

Please check the MR description for all the relevant details and changes I've made. Let me know if you need any updates.

Did

`ag -G Middleware -Q 'HttpKernelInterface $'`

to check the construct parameters, and

`ag -G Middleware -Q '= $http_kernel'`

to check the names of the properties, and it all looks good.

Thanks!

I read the IS, comments and the MR. I didn't find any unanswered questions.

Is there a grep command to confirm that all instances have been changed?

And what about tests? For example. this changes the name in core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php but not in the associated test, core/tests/Drupal/Tests/Core/StackMiddleware/NegotiationMiddlewareTest.php. That seems odd, at least to me. I think it would be better to change standardize them all. Is there a plan to do this in tests? I am not one to expand scope but it might make sense here.

> $this->app = $this->prophesize(HttpKernelInterface::class);

Good point about tests. I can see 3 tests in core/tests/Drupal/Tests/Core/StackMiddleware that mock an http kernel, and they get stacked with other kernels.

It's highly unlikely someone would be doing step debugging here -- IIRC it all goes haywire with mocks -- but let's change it for consistency.

> Is there a grep command to confirm that all instances have been changed?

I came up with this when I posted the issue:

> `ag -G Middleware __construct`

I performed Novice Triage on this issue. I am leaving the Novice tag on this issue because I think the requested changes from @quietone and confirmed by @joachim are clear. As well, we can confirm the uses again and update the issue summary to clarify how we found the changes.

I'll look into this issue at DrupalCon Atlanta 2025, probably until the end of the day.

#Atlanta2025 working on this issue with @igorgoncalves

Pushed a few commits to update variable names in Middleware test files and resolve the merge conflict in `NegotiationMiddleware.php`.

I've been mentoring @kwolford121 throughout the day. All the remaining names related to middleware are renamed. @kwolford121 is creating a follow-up issue for non-middleware renaming.