[Service Bus] Clarify what retry options govern (Azure#38146)

* [Service Bus] Clarify what retry options govern

The focus of these changes is to add text to clarify what the `ServiceBusClientOptions.RetryOptions` govern and explicitly mention that developers are responsible for handling failures and performing retries for message processing done by the application.

* Update sdk/servicebus/Azure.Messaging.ServiceBus/src/Client/ServiceBusClientOptions.cs

Co-authored-by: JoshLove-msft <54595583+JoshLove-msft@users.noreply.github.com>

* Reword to incorporate feedback

* Remove trailing whitespace

* Trailing whitespace (again)

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Co-authored-by: JoshLove-msft <54595583+JoshLove-msft@users.noreply.github.com>

Author: jsquire

sdk/servicebus/Azure.Messaging.ServiceBus/src/Client/ServiceBusClientOptions.cs

@@ -86,10 +86,15 @@ public TimeSpan ConnectionIdleTimeout
         }
 
         /// <summary>
-        /// The set of options to use for determining whether a failed operation should be retried and,
+        /// The set of options to use for determining whether a failed service operation should be retried and,
         /// if so, the amount of time to wait between retry attempts.  These options also control the
-        /// amount of time allowed for receiving messages and other interactions with the Service Bus service.
+        /// amount of time allowed for the individual network operations used for interactions with the Service Bus service.
         /// </summary>
+        /// <remarks>
+        /// The retry options are only considered for interactions with the Service Bus service. They do not apply to failures in the
+        /// <see cref="ServiceBusProcessor.ProcessMessageAsync" /> handler. Developers are responsible for error handling and retries
+        /// as part of their event handler.
+        ///</remarks>
         public ServiceBusRetryOptions RetryOptions
         {
             get => _retryOptions;