Add search to the podcasts list on the Watch app.

It will be hard to find podcasts if you have a large collection on the Watch so it will be good to include a search at the top of the page.

Start at the podcasts list entry point in the Watch app and trace how the collection is displayed. Add a search control at the top that narrows the visible podcasts, then verify that searching a large collection produces the expected filtered list.

Written by the indexing model from the issue text.