[meta] Remove some lazy proxy services

Problem/Motivation

Some services are declared with lazy: true and have a proxy class to instantiate them on demand.

For example, the plugin.cache_clearer service is lazy but it is always accessed directly from the container as follows:

\Drupal::service('plugin.cache_clearer')->clearCachedDefinitions();

The returned service is a lazy proxy to the real service, but calling clearCachedDefinitions() immediately negates any benefit of using the lazy proxy.

Steps to reproduce

Proposed resolution

Remove lazy: true and associated proxy classes from services that do not need to be lazy.
Use modern Symfony features such as tagged service iterators where they would be useful.

Remaining tasks

Identify which services this applies to.

User interface changes

API changes

Data model changes

Release notes snippet