Implement Updates Sidebar

[alonp99]

• Create a new endpoint in the backend API to create an update: POST /case-management/updates.
• Define the Update model in the backend with the specified fields (id, createdAt, updatedAt, sender, receivers).
• Create a new endpoint to retrieve a list of updates: GET /case-management/updates.
• Display the list of updates in the sidebar using ShadCN's components.
• Ensure proper data fetching and rendering of the updates list.