Avoid t() calls, instead use \Drupal\Core\StringTranslation\StringTranslationTrait and $this->t()

Problem/Motivation

After running coder for Drupal best practices, I found the following issues regarding t() calls:

FILE: /advancedqueue/src/Plugin/AdvancedQueue/Backend/BackendBase.php
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FOUND 0 ERRORS AND 2 WARNINGS AFFECTING 2 LINES
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 103 | WARNING | t() calls should be avoided in classes, use \Drupal\Core\StringTranslation\StringTranslationTrait and $this->t() instead
 104 | WARNING | t() calls should be avoided in classes, use \Drupal\Core\StringTranslation\StringTranslationTrait and $this->t() instead
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FILE: /advancedqueue/src/Form/QueueForm.php
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FOUND 0 ERRORS AND 2 WARNINGS AFFECTING 2 LINES
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 123 | WARNING | t() calls should be avoided in classes, use \Drupal\Core\StringTranslation\StringTranslationTrait and $this->t() instead
 124 | WARNING | t() calls should be avoided in classes, use \Drupal\Core\StringTranslation\StringTranslationTrait and $this->t() instead
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FILE: /advancedqueue/src/QueueListBuilder.php
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FOUND 0 ERRORS AND 1 WARNING AFFECTING 1 LINE
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 53 | WARNING | t() calls should be avoided in classes, use \Drupal\Core\StringTranslation\StringTranslationTrait and $this->t() instead
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Proposed resolution

Need to replace t() calls with $this->t() wherever required.