Replace t() with $this->t()

I assigned the task myself because I plan to fix this issue and make a Merge Request.
Please do not work on this issue.

Replace t() with $this->t(). Also I removed t() function from this code:

throw new FieldException(t('A field with a different type already exists on destination entity type @entity-type.', [
  '@entity-type' => $destination_entity_type_id,
]));

in the FieldCloner.php because exceptions should not be translated.

Committed. Thanks!

Automatically closed - issue fixed for 2 weeks with no activity.