Add new Medium "Now Playing" widget

[jgcaruso]

Follow up to https://github.com/Automattic/pocket-casts-ios/pull/1343 that introduces the new medium Now Playing widget from Lkt7fuf9Nq3XvfAFPCfpTD-fi-995_4119

iOS 17

light	dark

iOS 16

light	dark

To test

1. pull branch, build and run on device or simulator
2. Open the widget chooser, scroll through the options for Pocket Casts. You should see the new medium Now Playing widget in both styles after the "small" variation
3. Add one (or both) to your home screen
4. The widget should match the designs
5. If you added the white version, flipping into "dark" mode should turn it black. Or if it was already black, flipping into "light" mode should turn it white.
6. In iOS 17, the widget should be interactive. Tapping play should start the podcast, tapping pause should stop it.
   • tapping anywhere else should open Pocket Casts to the episode
7. In iOS 16, tapping anywhere should open Pocket Casts to the episode
8. When there isn't a "Now Playing" episode, the default state will match the "small" size and simply show the current Pocket Casts icon -- Waiting on design to review this since it won't work well as-is if a custom icon is chosen p1720121313396209-slack-C05RR9P9RAT

Checklist

• [ ] I have considered if this change warrants user-facing release notes and have added them to CHANGELOG.md if necessary.
• [ ] I have considered adding unit tests for my changes.
• [ ] I have updated (or requested that someone edit) the spreadsheet to reflect any new or changed analytics.