[improve][client] Enhance error handling for non-exist subscription in consumer creation (#23254)

(cherry picked from commit 7fc88d6)

Author: Shawyeok

Diff for: pulsar-broker/src/test/java/org/apache/pulsar/client/api/MultiTopicsConsumerTest.java

@@ -413,8 +413,9 @@ public void testSubscriptionNotFound() throws PulsarAdminException, PulsarClient
                     .isAckReceiptEnabled(true)
                     .subscribe();
             assertTrue(singleTopicConsumer instanceof ConsumerImpl);
+        } catch (PulsarClientException.SubscriptionNotFoundException ignore) {
         } catch (Throwable t) {
-            assertTrue(t.getCause().getCause() instanceof PulsarClientException.SubscriptionNotFoundException);
+            fail("Should throw PulsarClientException.SubscriptionNotFoundException instead");
         }
 
         try {
@@ -424,8 +425,9 @@ public void testSubscriptionNotFound() throws PulsarAdminException, PulsarClient
                     .isAckReceiptEnabled(true)
                     .subscribe();
             assertTrue(multiTopicsConsumer instanceof MultiTopicsConsumerImpl);
+        } catch (PulsarClientException.SubscriptionNotFoundException ignore) {
         } catch (Throwable t) {
-            assertTrue(t.getCause().getCause() instanceof PulsarClientException.SubscriptionNotFoundException);
+            fail("Should throw PulsarClientException.SubscriptionNotFoundException instead");
         }
 
         pulsar.getConfiguration().setAllowAutoSubscriptionCreation(true);

Diff for: pulsar-client-api/src/main/java/org/apache/pulsar/client/api/PulsarClientException.java

@@ -1144,6 +1144,8 @@ public static PulsarClientException unwrap(Throwable t) {
             newException = new TransactionConflictException(msg);
         } else if (cause instanceof TopicDoesNotExistException) {
             newException = new TopicDoesNotExistException(msg);
+        } else if (cause instanceof SubscriptionNotFoundException) {
+            newException = new SubscriptionNotFoundException(msg);
         } else if (cause instanceof ProducerFencedException) {
             newException = new ProducerFencedException(msg);
         } else if (cause instanceof MemoryBufferIsFullError) {