chore: replace global binds with dedicated service definition

config/services.yaml

@@ -67,10 +67,6 @@ services:
             $termsAndConditionsUrl: '%terms_and_conditions_url%'
             $logger: '@monolog.logger.core'
             $environment: '%kernel.environment%'
-            $mailjetApiKey: '%env(default::MAILJET_API_KEY)%'
-            $mailjetApiSecret: '%env(default::MAILJET_API_SECRET)%'
-            $mailjetApiBaseUrl: '%env(default::MAILJET_API_BASE_URL)%'
-            $mailjetNewsletterListId: '%env(default::MAILJET_NEWSLETTER_LIST_ID)%'
 
     # makes classes in src/ available to be used as services
     # this creates a service per class whose id is the fully-qualified class name
@@ -191,3 +187,10 @@ services:
             $defaults:
                 from: '%default_email_from%'
                 to: '%default_email_to%'
+
+    App\Service\MailjetApiClient:
+        arguments:
+            $mailjetApiKey: '%env(default::MAILJET_API_KEY)%'
+            $mailjetApiSecret: '%env(default::MAILJET_API_SECRET)%'
+            $mailjetApiBaseUrl: '%env(default::MAILJET_API_BASE_URL)%'
+            $mailjetNewsletterListId: '%env(default::MAILJET_NEWSLETTER_LIST_ID)%'