show response status code from k8s API in UI

plugins/kubernetes/src/components/KubernetesContent/ErrorPanel.test.tsx

@@ -76,7 +76,7 @@ describe('ErrorPanel', () => {
     expect(getByText('Cluster: THIS_CLUSTER')).toBeInTheDocument();
     expect(
       getByText(
-        "Error fetching Kubernetes resource: 'some/resource', error: SYSTEM_ERROR",
+        "Error fetching Kubernetes resource: 'some/resource', error: SYSTEM_ERROR, status code: 500",
       ),
     ).toBeInTheDocument();
   });

plugins/kubernetes/src/components/KubernetesContent/ErrorPanel.tsx

@@ -29,7 +29,7 @@ const clustersWithErrorsToErrorMessage = (
         {c.errors.map((e, j) => {
           return (
             <Typography variant="body2" key={j}>
-              {`Error fetching Kubernetes resource: '${e.resourcePath}', error: ${e.errorType}`}
+              {`Error fetching Kubernetes resource: '${e.resourcePath}', error: ${e.errorType}, status code: ${e.statusCode}`}
             </Typography>
           );
         })}