fix(linker): fixed prompt

* when we want to prompt login but we still want to do the offline
access then in the customQueryParams['prompt'] needs to be both 'login'
and 'prompt' so in the end the value needs to be 'prompt login'

apps/linker/src/assets/config/defaultConfig.json

@@ -8,7 +8,7 @@
     "oauth_post_logout_redirect_uri": "",
     "oauth_redirect_uri": "http://localhost:4201/api-callback",
     "oauth_load_user_info": true,
-    "oauth_scopes": "openid profile perun_api perun_admin target user_identifiers",
+    "oauth_scopes": "openid profile perun_api offline_access target user_identifiers",
     "oauth_response_type": "code",
     "oauth_offline_access_consent_prompt": true
   },

libs/perun/services/src/lib/auth.service.ts

@@ -59,11 +59,19 @@ export class AuthService {
     }
     if (sessionStorage.getItem('mfa_route')) {
       customQueryParams['acr_values'] = 'https://refeds.org/profile/mfa';
-      customQueryParams['prompt'] = 'login';
+      if (customQueryParams['prompt']) {
+        customQueryParams['prompt'] += ' login';
+      } else {
+        customQueryParams['prompt'] = 'login';
+      }
       customQueryParams['max_age'] = '0';
     }
     if (this.store.getProperty('application') === 'Linker') {
-      customQueryParams['prompt'] = 'login';
+      if (customQueryParams['prompt']) {
+        customQueryParams['prompt'] += ' login';
+      } else {
+        customQueryParams['prompt'] = 'login';
+      }
       const selectedIdP = parseQueryParams('idphint', location.search.substring(1));
       if (selectedIdP) {
         customQueryParams['idphint'] = selectedIdP;