Client config not render blocking (#12300)

Changes for performance improvement.
The primary improvements include replacing GraphQL queries with
REST-based client configuration fetching and making the client config
non render-blocking

packages/twenty-front/src/testing/graphqlMocks.ts

@@ -124,6 +124,9 @@ export const graphqlMocks = {
         },
       });
     }),
+    http.get(`${REACT_APP_SERVER_BASE_URL}/client-config`, () => {
+      return HttpResponse.json(mockedClientConfig);
+    }),
     metadataGraphql.query(
       getOperationName(FIND_MANY_OBJECT_METADATA_ITEMS) ?? '',
       () => {