Use events to flush all caches on container rebuild

Problem/Motivation

Currently, container rebuild and flushing all caches is done with procedural functions
drupal_rebuild(), drupal_flush_all_caches(), _drupal_flush_css_js().

In #3014752: Convert drupal_flush_all_caches() function to a Cache Clearer service it is being proposed to convert these to a cache rebuilder class.
However, this still leaves a hard-coded piece of code to do all the tasks needed on container rebuild.

As an alternative, I propose to introduce events to decentralize these tasks.
(in fact this is not mutually exclusive with the cache rebuilder class)

Steps to reproduce

Proposed resolution

Introduce one event for "container rebuilt".
Introduce another event for "all caches should be cleared".
Add a subscriber for "container rebuilt" that triggers the "all caches should be cleared" event.
Let different services subscribe to these events.

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet