[Feature Request]: Add notify button for scheduled live streams

### Guidelines

- [X] I have searched the issue tracker for [open](https://github.com/FreeTubeApp/FreeTube/issues?q=is%3Aopen+is%3Aissue) and [closed](https://github.com/FreeTubeApp/FreeTube/issues?q=is%3Aissue+is%3Aclosed) issues 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

Scheduled live streams do say when they start but sometimes people forget that they start a certain time

### Proposed Solution

Add a button to notify the user when the stream starts

### Alternatives Considered

None.

### Issue Labels

improvement to existing feature

### Additional Information

This was mentioned by @ThisNekoGuy in their bug report in #812 but as the original issue is solved i created this feature request