Delete downloads on unsubscribe

[bjtitus]

Fixes PCIOS-380

This changes two behaviors regarding downloads:

• Any time a podcast is unsubscribed from the device, all downloads are removed regardless of playlist status. The user agrees to a prompt to explicitly remove them and this behavior was changed in Keep downloads & Up Next queue on unsubscribe #3538
• Downloads are not removed when running the regular cleanup task if they are part of a manual playlist. This is because the Podcast info may have been fetched for display and we don't know the difference, so this would delete all episodes manually added from Discover from a podcast a user didn't subscribe to.

To test

Unsubscribe deletion

Must be signed in to account

1. Subscribe to a podcast from Discover
2. Unsubscribe from the podcast
3. Navigate back to that podcast on Discover
4. ✅ Ensure downloaded episodes are deleted

Non-subscribed Manual Playlist Episode

1. Add an episode from Discover to a Manual playlist from a podcast you don’t subscribe to
2. Download the episode
3. Pull to refresh
4. ✅ Ensure the download remains

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.

[dangermattic]

	1 Warning
⚠️	This PR is assigned to the milestone 8.1 ❄️. The due date for this milestone has already passed. Please assign it to a milestone with a later deadline or check whether the release for this milestone has already been finished.

Generated by 🚫 Danger

[SergioEstevao]

Working correctly.
Episode in manual playlists are not being deleted when refreshing.