[feature][client-cpp] Support inclusive seek for cpp client (#17209)

Fixes #17186

### Motivation

There are some cases in which it is useful to be able to include current
position of the message when reset of cursor was made.

### Modifications

* Support inclusive seek in c++ consumers.
* Add a unit test to verify.

Author: Demogorgon314

pulsar_test.py

@@ -546,7 +546,7 @@ def test_reader_on_specific_message(self):
         # The reset would be effectively done on the next position relative to reset.
         # When available, we should test this behaviour with `startMessageIdInclusive` opt.
         from_msg_idx = last_msg_idx
-        for i in range(from_msg_idx, num_of_msgs):
+        for i in range(from_msg_idx + 1, num_of_msgs):
             msg = reader2.read_next(TM)
             self.assertTrue(msg)
             self.assertEqual(msg.data(), b"hello-%d" % i)
@@ -896,7 +896,7 @@ def test_seek(self):
         consumer.seek(ids[50])
         time.sleep(0.5)
         msg = consumer.receive(TM)
-        self.assertEqual(msg.data(), b"hello-50")
+        self.assertEqual(msg.data(), b"hello-51")
 
         # ditto, but seek on timestamp
         consumer.seek(timestamps[42])
@@ -921,9 +921,9 @@ def test_seek(self):
         reader.seek(ids[33])
         time.sleep(0.5)
         msg = reader.read_next(TM)
-        self.assertEqual(msg.data(), b"hello-33")
-        msg = reader.read_next(TM)
         self.assertEqual(msg.data(), b"hello-34")
+        msg = reader.read_next(TM)
+        self.assertEqual(msg.data(), b"hello-35")
 
         # seek on timestamp
         reader.seek(timestamps[79])