add new feature flag to enable faster refresh of WTS token

This is based on the assumption that workspace and WTS are not always bundled
together in data portal installations. I.e. one could have a workspace without
a WTS.

docs/portal_config.md

@@ -182,6 +182,7 @@ Below is an example, with inline comments describing what each JSON block config
     "explorerFilterValuesToHide": ["array of strings"], // optional, Values set in array will be hidden in guppy filters. Intended use is to hide missing data category from filters, for this it should be set to the same as `missing_data_alias` in Guppy server config
     "studyRegistration": true, // optional, whether to enable the study registration feature
     "workspaceRegistration": true, // optional, whether to enable the workspace registration feature
+    "workspaceTokenServiceRefreshTokenAtLogin": true, // optional, whether to refresh the WTS token directly at portal login (recommended mode). If not set, this refresh happens only when the user enters the workspace section of the portal (default/old/previous mode).
   },
   "dataExplorerConfig": { // required only if featureFlags.explorer is true; configuration for the Data Explorer (/explorer); can be replaced by explorerConfig, see Multi Tab Explorer doc
     "charts": { // optional; indicates which charts to display in the Data Explorer

src/index.jsx

@@ -69,8 +69,10 @@ import NotFound from './components/NotFound';
 import ErrorPage403 from './components/ErrorPage403';
 import { initWorkspaceRefreshToken } from './Workspace/WorkspaceRefreshToken';
 
-// start workspace session for WTS
-initWorkspaceRefreshToken();
+if (isEnabled('workspaceTokenServiceRefreshTokenAtLogin')) {
+  // start workspace session for WTS
+  initWorkspaceRefreshToken();
+}
 
 // monitor user's session
 sessionMonitor.start();