The Welcome Home Screen: Dedicated Download Apps Dialog

[justjanne]

Part of Epic #22463

As part of the new user onboarding flow, we want to provide a better experience for the "download apps" action. This should be accomplished with a new, dedicated dialog for downloading apps.

[daniellekirkwood]

We deprioritised this from the MVP so that we could get the checklist into the 26th July RC. We will update with this functionality for the next release.