Inject services in place of \Drupal calls in file module hook classes

Generated with the help of an LLM.

Problem/Motivation

Two autowired hook classes in the file module call \Drupal when they could have the service injected:

• FileHooks::help(): \Drupal::moduleHandler() (2 calls).
• FileRequirements::runtime(): \Drupal::request() (1 call).

Steps to reproduce

Proposed resolution

Add a ModuleHandlerInterface constructor parameter to FileHooks. Add a RequestStack constructor parameter to FileRequirements. Autowiring supplies both.

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet