[BUG] Cannot send tombstone to azure event hub

[fillsinger]

Describe the bug
According to the Event Hub documentation "Client applications set tombstones by sending a new event with an existing key and a null event payload.”
However, the class com.azure.messaging.eventhubs.EventData does NOT allow to have a null body.

Hence, at the moment it is not possible to send a proper tombstone event to the azure event hub, using the azure sdk for java.

Exception or Stack Trace

java.lang.NullPointerException: 'body' cannot be null.

	at java.base/java.util.Objects.requireNonNull(Objects.java:259)
	at com.azure.messaging.eventhubs.EventData.<init>(EventData.java:64)

To Reproduce
Run the provided code snippet or have a look at the code of the com.azure.messaging.eventhubs.EventData.
There you can see that null is not permitted as a value for body

Code Snippet

try (EventHubProducerClient producer = new EventHubClientBuilder()
                .connectionString("Endpoint=sb://.........", "sandbox")
                .buildProducerClient()) {

            producer.send(List.of(new EventData((byte[]) null)
                    .setMessageId("123")
                    .setContentType("application/avro+MagnoliaPagePublish;version=1")), new SendOptions()
                    .setPartitionKey("0"));

        }

Expected behavior
It is expected to be able to create an event with a null body, in order to provide correct tombstone events to the event hub.

Setup (please complete the following information):

• OS: iOS 15.3.1
• IDE: IntelliJ
• Library/Libraries: azure-messaging-eventhubs:5.20.0, azure-core-amqp:2.9.15
• Java version: 21

Information Checklist
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