Display a loading indicator when fetching the next page

[MGaetan89]

Pull request

Description

Currently, when fetching the next page using Paging, there is no loading indicator to tell the user that something is happening.
Now, there is an indicator shows while the page is being loaded.

The impacted screens are in "Lists" and "Search", both on the mobile and TV demo aps.

Changes made

As explained above.

Checklist

• Your branch has been rebased onto the main branch.
• APIs have been properly documented (if relevant).
• The documentation has been updated (if relevant).
• New unit tests have been written (if relevant).
• The demo has been updated (if relevant).
• All pull request status checks pass.