fix: CLARK-CLIENT-1E - Prevent TypeError on dashboard learning object list

[sentry]

This PR addresses CLARK-CLIENT-1E, a TypeError occurring on the dashboard when evaluating learningObjects.length.

Root Cause:
The loading flag was set to false prematurely in dashboard.component.ts before asynchronous HTTP requests for learning objects (getDraftLearningObjects, getReleasedLearningObjects) had completed. This exposed undefined arrays to the dashboard list component, leading to a crash when .length was accessed.

Changes Made:

1. dashboard.component.ts: Modified getDraftLearningObjects and getReleasedLearningObjects to await the searchService.getUsersLearningObjects calls. This ensures that the component waits for data to be fetched and assigned before proceeding.
2. dashboard.component.ts: Initialized workingLearningObjects to an empty array ([]) to prevent potential undefined access if rendering occurs before data is fully loaded. releasedLearningObjects was intentionally left uninitialized to preserve existing query parameter handling logic that relies on its undefined state.
3. dashboard.component.ts: Ensured this.loading = false is only set after both getDraftLearningObjects and getReleasedLearningObjects have completed their data fetching.

Fixes CLARK-CLIENT-1E

_{This PR was automatically generated by Sentry. You can adjust this setting at any time.}