Issue #2787259 by dpi: RecipientGatewayEvent::getGatewaysSorted does not return any gateways
Added test coverage for \Drupal\sms\Event\RecipientGatewayEvent
Add ID detect to createMemoryGateway so the id passed to settings is correct.
Issue #2776751 by dpi: Harmonise APIs for Entity\SmsMessageInterface and Message\SmsMessageInterface
Allowing standard messages on queue(), not just entity.
Promoted set/getDirection from message entity to common method.
Promoted direction tests to message trait, which enables coverage on both message classes.
Fixed YAML parsing issue introduced by updating symfony/yaml
Behaviour change was introduced sometime between 2.8.4 (bundled with core) and 2.8.9 (latest).
New behaviour adds a trailing newline after '[username]'.
Changing the multiline string character fixes this trailing newline.