test(bench): add benchmark suite

[xHeaven]

I've updated the existing phpbench dependency to the stable version.

I've also added kernel boot, container, view, and request-response lifecycle benchmarks.

I've also added the CI (from the highlight package) and a composer script you can run on your own PC.

[innocenzi]

I suggest you add yourself as code owner of the workflow before we merge!

[xHeaven]

I suggest you add yourself as code owner of the workflow before we merge!

Done!
The failing test from before is a flaky test_now.