style(iot-hub): polish getInstalledItemUrl readability

- Guard the helper against a missing descriptor by short-circuiting
  to null up front instead of letting the switch crash on
  `undefined.type`.
- Expand the inline single-line `case 'X': … break;` arms in the
  switch so each branch reads on its own line, matching the
  formatting of the already-multi-line CALCULATED_FIELD /
  ALARM_RULE arms.

ui-ngx/src/app/shared/models/iot-hub/iot-hub-installed-item.models.ts

@@ -101,12 +101,21 @@ export interface IotHubInstalledItem extends BaseData<{id: string}> {
 }
 
 export const getInstalledItemUrl = (descriptor?: IotHubInstalledItemDescriptor): string | null => {
+  if (!descriptor) {
+    return null;
+  }
   let entityId: string | null = null;
   let entityType: EntityType | null = null;
   let query: string | null = null;
   switch (descriptor.type) {
-    case 'WIDGET': entityId = descriptor.widgetTypeId?.id; entityType = EntityType.WIDGET_TYPE; break;
-    case 'DASHBOARD': entityId = descriptor.dashboardId?.id; entityType = EntityType.DASHBOARD; break;
+    case 'WIDGET':
+      entityId = descriptor.widgetTypeId?.id;
+      entityType = EntityType.WIDGET_TYPE;
+      break;
+    case 'DASHBOARD':
+      entityId = descriptor.dashboardId?.id;
+      entityType = EntityType.DASHBOARD;
+      break;
     case 'CALCULATED_FIELD':
     case 'ALARM_RULE':
       entityId = descriptor.entityId?.id;
@@ -115,8 +124,14 @@ export const getInstalledItemUrl = (descriptor?: IotHubInstalledItemDescriptor):
         query = 'selectedTab=cf';
       }
       break;
-    case 'RULE_CHAIN': entityId = descriptor.ruleChainId?.id; entityType = EntityType.RULE_CHAIN; break;
-    case 'SOLUTION_TEMPLATE': entityId = descriptor.dashboardId?.id; entityType = EntityType.DASHBOARD; break;
+    case 'RULE_CHAIN':
+      entityId = descriptor.ruleChainId?.id;
+      entityType = EntityType.RULE_CHAIN;
+      break;
+    case 'SOLUTION_TEMPLATE':
+      entityId = descriptor.dashboardId?.id;
+      entityType = EntityType.DASHBOARD;
+      break;
   }
   if (entityType && entityId) {
     let url = getEntityDetailsPageURL(entityId, entityType);