Clean up coding standards issues for DSFR before security coverage submission

The concept of Drupal CS has been added. The sniffs listed in https://www.drupal.org/files/issues/2025-07-24/output.txt → have been addressed in this fork: https://git.drupalcode.org/issue/dsfr-3537568/-/compare/2.1.x...2.1.x?fr...

However, some points warrant further discussion:

• What is the benefit of abstracting t()? In my opinion, there is none.
• Form class: While the desire to minimize code is understandable, I see drawbacks:
  1. It unnecessarily complicates the code.
  2. Methods with numerous parameters feel suboptimal.
• Naming conventions need review in certain areas. For example (non-exhaustive):
  https://git.drupalcode.org/project/dsfr/-/blob/2.1.x/src/settings/Tools.... getUrl() returning an array instead of a Drupal\Core\Url object could cause confusion.
  https://git.drupalcode.org/project/dsfr/-/blob/2.1.x/src/settings/Form.p... method called margin() to get "margin options" causes confusion.

Naming conventions should also be taken into consideration in this issue.