[hackday] Added tests trying to reproduce bug #11663, throwing AccessDeniedHttpException in kernel request listener

I tried to fix #11663, assuming it was a generic problem with HTTP exceptions thrown in kernel event listeners, but I cannot reproduce it.

As I wrote a couple of tests on the way, I thought it wouldn't hurt to PR them. Yay, TDD!

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | 11663 (cannot reproduce?)
| License       | MIT

ps: Hi from the hackday.