KC: Display a clear message if connector already exists (#1839)

Co-authored-by: Roman Zabaluev <rzabaluev@provectus.com>

kafka-ui-react-app/src/redux/actions/__test__/thunks/connectors.spec.ts

@@ -192,7 +192,7 @@ describe('Thunks', () => {
         actions.createConnectorAction.failure({
           alert: {
             subject: 'local-first',
-            title: 'Kafka Connect Connector Create',
+            title: `Connector with name ${connectorName} already exists`,
             response: {
               status: 404,
               statusText: 'Not Found',

kafka-ui-react-app/src/redux/actions/thunks/connectors.ts

@@ -111,7 +111,7 @@ export const createConnector =
       const response = await getResponse(error);
       const alert: FailurePayload = {
         subject: [clusterName, connectName].join('-'),
-        title: `Kafka Connect Connector Create`,
+        title: `Connector with name ${newConnector.name} already exists`,
         response,
       };
       dispatch(actions.createConnectorAction.failure({ alert }));