Improve download buttons UX

[alecgorge]

• [ ] The download a complete show should prompt before downloading
• [x] Test canceling/deleting a whole show while it is downloaded
• [ ] Should the download button have text above it to make clear that it is a download button? Do we need a different button?
• [x] You should be able to download the whole show if you only have part of it downloaded
• [x] You should be able to delete everything that is downloaded for the show

[farktronix]

I really don't like confirmation prompts, so I'd rather the entire show just starts downloading if you tap on the download icon. Relisten only downloads three items at a time, so if you decide it was a mistake and cancel the download (by tapping on the download icon again) it's not too expensive to back out of it. This also matches how the Apple Music app works.

I'm not a fan of having both the download button and the trash can button. I added that because it was the simplest to implement, but some better solutions that I've thought of are:

• Add a long tap/force tap on the download button that brings up a sheet that lets you delete everything
• Add a ... icon to the favorite/download/share bar that has a delete everything option

[alecgorge]

The only thing left to do here is to indicate on the "Delete All" button that it will stop any in progress downloads as well.