Porting workflow_actions [D7>D8>D11]

Problem/Motivation

The Workflow module provides the following Actions, already since D7 versions:
- Change a node to new (given) Workflow state
- Change a node to next Workflow state
They should also work with the contrib Views Bulk Operations (VBO) module.

In D7, These actions were implemented in submodule workflow_actions.
The actions can be found under admin/config/system/actions .
However, the submodule workflow_actions does not provide actions - it provides triggers. So, when porting to D8, rename the module to 'workflow_trigger'.
The triggers can be seen under /admin/structure/trigger/node, and consists of a list of entries like:
Trigger: When node <node_type> moves <field_name> from <from-state> to <to_state>
Trigger module is removed from core. See #764558: Remove Trigger module from core and https://www.drupal.org/project/trigger for the current status.

In D8, both actions are ported as an Action plugin in workflow/src/Plugin/Action.
They can be found under admin/config/system/actions when enabling the core Actions module. The Actions UI module is deprecated in Drupal 10.3 and will be removed from Drupal 11.0.

Remaining tasks

In D9, when testing, some errors were found, and also a lot of @todo code.
- config was not written;
- schema.yml files are not complete;
- only applicable for 'node' entity types;
- ...

User interface changes

- Action UI module as per 10.3.
- When working with VBO, add the Global: Views bulk operations field to the view. There, you can disable the 'confirmation step' per each added Action..

API changes

Data model changes