Issue #3479339: Add strict checking of valid phases for email functions

src/BaseEmailTrait.php

src/Email.php

src/EmailInterface.php

src/InternalEmailInterface.php

src/Processor/CallbackEmailProcessor.php

src/Processor/EmailProcessorBase.php

src/Processor/EmailProcessorCustomBase.php

src/Processor/EmailProcessorInterface.php

tests/modules/symfony_mailer_test/src/MailerTestTrait.php

tests/src/Kernel/EmailAdjusterTest.php

tests/src/Kernel/EmailInterfaceTest.php