Fix subclassing and stop overriding constructors

Problem/Motivation

Add object that implements FactoryInterface or ContainerFactoryPluginInterface should have dependencies injected via ::create and not ::__construct(). This allows parent classes to change their constructor without breaking any code.

See

• https://www.drupal.org/node/3076421 →
• https://www.previousnext.com.au/blog/safely-extending-drupal-8-plugin-cl...
• https://events.drupal.org/seattle2019/sessions/drupal-9-coming-getting-y...

Proposed resolution

Fix subclassing and stop overriding constructors.

Remaining tasks

• Remove __construct() implementations from plugins