Notification Service Redesign

...a/org/opengroup/osdu/notification/api/PubsubEndpoint.java

...ngroup/osdu/notification/service/NotificationHandler.java

...ngroup/osdu/notification/service/SubscriptionHandler.java

...notification/service/interfaces/INotificationHandler.java

...notification/service/interfaces/ISubscriptionHandler.java

.../opengroup/osdu/notification/api/PubsubEndpointTests.java

...azure/pubsub/extractor/EventGridRequestBodyExtractor.java

...rovider/azure/pubsub/utils/EventGridHandshakeHandler.java

...vider/azure/pubsub/EventGridRequestBodyExtractorTest.java

...du/notification/pubsub/EventGridHandshakeHandlerTest.java