Replace usages of the deprecated drupal_set_message() function

@nkoporec / alesbencina Thanks for working on this issue. I recommend installing in your code editor, so you get notified when code violates the Drupal coding standards. You can find instructions at https://www.drupal.org/node/1419988

1. +++ b/src/Form/PathautoAdminDelete.php
   @@ -20,13 +21,21 @@ class PathautoAdminDelete extends FormBase {
   +   * Drupal messenger service
   

   Doc comment short description must end in a full stop.

2. +++ b/src/Form/PathautoAdminDelete.php
   @@ -20,13 +21,21 @@ class PathautoAdminDelete extends FormBase {
   -   *   The alias type manager.
   

   This parameter comment is required by the Drupal coding standards

3. +++ b/src/Form/PathautoAdminDelete.php
   @@ -20,13 +21,21 @@ class PathautoAdminDelete extends FormBase {
   +   * @param \Drupal\Core\Messenger\MessengerInterface $messenger
   

   Missing parameter comment

4. +++ b/src/Form/PathautoAdminDelete.php
   @@ -20,13 +21,21 @@ class PathautoAdminDelete extends FormBase {
   +    $this->messengerService = $messenger;
   

   Let's call this property "messenger" in line with Drupal core

5. +++ b/src/Form/PathautoAdminDelete.php
   @@ -133,14 +143,17 @@ class PathautoAdminDelete extends FormBase {
   +        $this->messengerService->addMessage($this->t('All of your %label path aliases have been deleted.', [
   +          '%label' => $alias_type->getLabel()
   +        ]));
   

   A comma should follow the last multiline array item

6. +++ b/src/Form/PathautoAdminDelete.php
   @@ -168,17 +181,22 @@ class PathautoAdminDelete extends FormBase {
   +          \Drupal::service('messenger')->addMessage(t('All of your automatically generated %label path aliases have been deleted.',[
   +            '%label' => $label
   +          ]));
   

   A comma should follow the last multiline array item

7. +++ b/src/Form/PathautoAdminDelete.php
   @@ -168,17 +181,22 @@ class PathautoAdminDelete extends FormBase {
   +      \Drupal::service('messenger')->addMessage(t('An error occurred while processing @operation with arguments : @args',[
   +        '@operation' => $error_operation[0],
   +        '@args' => print_r($error_operation[0])
   +      ]));
   

   A comma should follow the last multiline array item

8. +++ b/src/Form/PathautoBulkUpdateForm.php
   @@ -149,15 +149,18 @@ class PathautoBulkUpdateForm extends FormBase {
   +      \Drupal::service('messenger')->addMessage(t('An error occurred while processing @operation with arguments : @args'),[
   +        '@operation' => $error_operation[0],
   +        '@args' => print_r($error_operation[0])
   +      ]);
   

   A comma should follow the last multiline array item.

9. +++ b/src/Form/PatternDisableForm.php
   @@ -12,6 +14,31 @@ use Drupal\Core\Url;
   +   * @param \Drupal\Core\Messenger\MessengerInterface $messenger
   

   Missing parameter comment.

10. +++ b/src/Form/PatternDisableForm.php
    @@ -12,6 +14,31 @@ use Drupal\Core\Url;
    +  public function __construct(MessengerInterface $messenger) {
    +    $this->messengerService = $messenger;
    +  }
    

    Let's call this property "messenger" in line with Drupal core

11. +++ b/src/Form/PatternDisableForm.php
    @@ -44,7 +71,9 @@ class PatternDisableForm extends EntityConfirmFormBase {
    +    $this->messengerService->addMessage(t('Disabled pattern %label.',[
    +      '%label' => $this->entity->label()
    +    ]));
    

    Use $this->t instead of t() when possible
    A comma should follow the last multiline array item.

12. +++ b/src/Form/PatternEditForm.php
    @@ -43,6 +44,11 @@ class PatternEditForm extends EntityForm {
    +   * @var \Drupal\Core\Messenger\MessengerInterface
    +   */
    +  protected $messengerService;
    

    Missing short description in doc comment.

13. +++ b/src/Form/PatternEditForm.php
    @@ -61,12 +68,14 @@ class PatternEditForm extends EntityForm {
    +   * @param \Drupal\Core\Messenger\MessengerInterface $messenger
    

    Missing parameter comment

14. +++ b/src/Form/PatternEditForm.php
    @@ -61,12 +68,14 @@ class PatternEditForm extends EntityForm {
    +    $this->messengerService = $messenger;
    

    Let's call this property "messenger" in line with Drupal core.

15. +++ b/src/Form/PatternEnableForm.php
    @@ -12,6 +14,28 @@ use Drupal\Core\Url;
    +   * @var \Drupal\Core\Messenger\MessengerInterface
    

    Missing short description in doc comment

16. +++ b/src/Form/PatternEnableForm.php
    @@ -12,6 +14,28 @@ use Drupal\Core\Url;
    +   * @param \Drupal\Core\Messenger\MessengerInterface $messenger
    

    Missing parameter comment

17. +++ b/src/Form/PatternEnableForm.php
    @@ -12,6 +14,28 @@ use Drupal\Core\Url;
    +  function __construct(MessengerInterface $messenger) {
    

    Visibility must be declared on method "__construct"

18. +++ b/src/Form/PatternEnableForm.php
    @@ -12,6 +14,28 @@ use Drupal\Core\Url;
    +    $this->messengerService = $messenger;
    

    Let's call this property "messenger" in line with Drupal core.

19. +++ b/src/Form/PatternEnableForm.php
    @@ -12,6 +14,28 @@ use Drupal\Core\Url;
    +  }
    

    Expected one blank line after function, found 0

20. +++ b/src/PathautoGenerator.php
    @@ -335,7 +335,7 @@ class PathautoGenerator implements PathautoGeneratorInterface {
    +      \Drupal::service('messenger')->addWarning($e->getMessage());
    

    Use dependency injection in classes when possible.

21. +++ b/src/Plugin/pathauto/AliasType/EntityAliasTypeBase.php
    @@ -274,7 +274,9 @@ class EntityAliasTypeBase extends ContextAwarePluginBase implements AliasTypeInt
    +      \Drupal::service('messenger')->addMessage(\Drupal::translation()->formatPlural(count($ids), 'Updated 1 %label URL alias.', 'Updated @count %label URL aliases.'),[
    +        '%label' => $this->getLabel()
    +      ]);
    

    - Use dependency injection in classes when possible
    - Expected one space after comma, found 0.
    - A comma should follow the last multiline array item.