[HttpKernel] decoupled TraceableEventDispatcher and Profiler
[HttpKernel] added LateDataCollectorInterface
feature#9170 Decoupled TraceableEventDispatcher from the Profiler (fabpot)

This PR was merged into the master branch.

Discussion
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Decoupled TraceableEventDispatcher from the Profiler

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | n/a

This PR removes the Profiler dependency on the TraceableEventDispatcher. That makes things more decoupled and cleaner. This PR also cleans up how profiles are stored; a Profile is now always stored only once.

I've created a `LateDataCollectorInterface` that is implemented for data collector that needs to get information from data that are available very late in the request process (when the request and the response are not even available anymore). The `lateCollect()` method is called just before the profile is stored.

We have 3 data collectors that implement that interface:

 * Time: As the traceable event dipsatcher gets inject timing information via the stopwatch about all events (including the `terminate` one), we need to get events from the stopwatch as late as possible.
 * Event: The traceable event dispatcher gathers all called listeners to determine non-called ones. To be able to accurately do that for all events (including the `terminate` one), we need to get the data as late as possible.
 * Memory: We want to get the memory as late as possible to get the most accurate number as possible

I'm not very happy with the name and as always, better suggestions would be much appreciated.

This is an extract from #9168

Commits
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5cedea2 [HttpKernel] added LateDataCollectorInterface
9c4bc9a [HttpKernel] decoupled TraceableEventDispatcher and Profiler