[Feature Request]: An option to hide recommendations from channels the user is not subscribed to

### Guidelines

- [x] I have [searched the issue tracker for open and closed issues](https://github.com/FreeTubeApp/FreeTube/issues?q=is%3Aissue+sort%3Arelevance-desc) that are similar to the feature request I want to file, without success.
- [x] I have searched the [documentation](https://docs.freetubeapp.io/) for information that matches the description of the feature request I want to file, without success.
- [x] This issue contains only one feature request.

### Problem Description

Many, if not most of the recommended videos in the "Up Next" tab are from popular channels, news platforms, etc. that some users have no interest in, particularly those users who only watch videos from channels they are subscribed to.

### Proposed Solution

Add an option to automatically hide recommended videos from channels that the user isn't subscribed to, while still having recommendations from the user's subscriptions.

### Alternatives Considered

N/A

### Issue Labels

new optional setting

### Additional Information

_No response_