Use OOP hook implementations

Problem/Motivation

Implement OOP hooks for better OOP & DI support, instead of having all hook logic in the module file.

Proposed resolution

Convert hook implementations to OOP hooks, with backwards compatibility.
See https://www.drupal.org/node/3442349 →

Remaining tasks

- Define hooks that can be converted into OOP hooks
- Create hook clas(ses) to logically bundle relevant hooks with their logic
- Add backwards compatibility support

User interface changes

N/A

API changes

N/A

Data model changes

N/A