feat: add bookmarking rooms functionality

[Cfla446]

What

1. Added room bookmarking functionality using persistent localStorage
2. Added useBookmarks hook using useSyncExternalStore for reactive state sync (avoiding syncing local storage via useEffect)
3. Updated individual room page UI with dynamic bookmark button/icon

Why

Bookmarks functionality was required to solve the issue of users wanting to find rooms they like or frequent quickly without having to search for it each time. Preferred rooms that are bookmarked are saved locally and can be retrieved or removed from localStorage.

How

Created useBookmarks hook using useSyncExternalStore (avoiding useEffect) to sync bookmark state of a room with localStorage. Bookmarks are treated as a JSONified array of room IDs, saved under the localStorage key 'bookmarks'.

The room page uses the useBookmarks hook to read the current bookmark state of the roomId, handling toggling of bookmarks (add/remove from array) on icon clicking (and updating visually), and persisting updates to localStorage.

Key checks:

• 🚩Attached screenshot or recording of the changes in related tickets
• Code comments where needed
• No new warnings

Automated tests:

• [] 🚩Unit tests added

Screenshot / Recording