add missing methods

Author: rajat08

pinecone/core/grpc/index_grpc.py

@@ -232,6 +232,12 @@ def result(self, timeout=None):
         except _MultiThreadedRendezvous as e:
             raise PineconeException(e._state.debug_error_string) from e
 
+    def exception(self,timeout=None):
+        with _MultiThreadedRendezvous as e:
+            raise PineconeException(e._state.debug_error_string) from e
+
+    def traceback(self,timeout=None):
+        return self._delegate.traceback(timeout=timeout)
 
 class GRPCIndex(GRPCIndexBase):