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

[efb4f5ff-1298-471a-8973-3d47447115dc]

Guidelines

• I have searched the issue tracker for open and closed issues that are similar to the feature request I want to file, without success.
• I have searched the documentation for information that matches the description of the feature request I want to file, without success.
• 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

[kommunarr]

For context, the original bug report seems to have been that the scheduled video entry wasn't appearing due to the limitations of RSS feeds. I'm not opposed to the idea of an in-app notification log for ongoing banners, certain toasts, and/or settings changes, but this one is a much more specific request and requires some broader changes (i.e., looking for scheduled subscribed videos whenever we load them). Real-time schedules are kinda funky too if it ends up being the case that streams can be rescheduled, and thus there also could be cases where we're giving notifications based off of the stale values.