t() calls should be avoided , use $this->t() instead in text module

Problem/Motivation

t() calls should be avoided in classes, use \Drupal\Core\StringTranslation\StringTranslationTrait and $this->t() instead.
Remove uses of t() in assertions has been done in the issue https://www.drupal.org/project/drupal/issues/3133726.
Remove all calls to t() wrapped in calls to drupalPostForm() will be done in the issue https://www.drupal.org/project/drupal/issues/3145005.

Steps to reproduce

Proposed resolution

Remaining tasks

Replace all remaning occurance of t() calls with $this->t() in classes.

User interface changes

API changes

Data model changes