Hazelcast autoconfiguration recognises hazelcast.xml and hazelcast.yaml but not hazelcast.yml

Similarly for clients, autoconfiguration recognises hazelcast-client.xml, hazelcast-client.yaml but not hazelcast-client.yml

Hazelcast itself accepts .yaml and .yml, see https://github.com/hazelcast/hazelcast/blob/master/hazelcast/src/main/java/com/hazelcast/internal/config/DeclarativeConfigUtil.java#L67

Enhancement is to make Spring Boot recognise yml suffix config files