Issue #3394193: Fix all PHPCS warnings and notices

src/Address.php

src/Email.php

src/Mailer.php

src/Plugin/EmailAdjuster/AbsoluteUrlEmailAdjuster.php

src/Plugin/EmailAdjuster/BodyEmailAdjuster.php

src/Plugin/EmailAdjuster/DefaultsEmailAdjuster.php

src/Plugin/EmailAdjuster/HooksEmailAdjuster.php

src/Plugin/EmailAdjuster/PlainEmailAdjuster.php

src/Plugin/EmailAdjuster/PlainOnlyEmailAdjuster.php

src/Plugin/EmailAdjuster/PriorityEmailAdjuster.php

src/Plugin/EmailAdjuster/SkipSendingEmailAdjuster.php

src/Plugin/EmailAdjuster/SubjectEmailAdjuster.php

src/Plugin/EmailAdjuster/ThemeEmailAdjuster.php

src/Plugin/EmailBuilder/CommerceOrderEmailBuilder.php

src/Plugin/EmailBuilder/ContactPageEmailBuilder.php

src/Plugin/EmailBuilder/SimplenewsNewsletterEmailBuilder.php

src/Plugin/EmailBuilder/UpdateEmailBuilder.php

src/Processor/EmailAdjusterManager.php

tests/modules/symfony_mailer_test/src/MailerTestTrait.php

tests/src/Functional/SymfonyMailerTestBase.php