feat: add no_shorts option for YouTube feeds

[3rd]

This adds a no_shorts option for YouTube feeds. It works by using the default video playlist feed instead of the channel feed. I find it very hard to express how much I hate YouTube shorts.

It would be cleaner to add support to "playlists" along with "channels", so that users could add whatever built-in/custom playlist they wish, but I feel wanting to remove shorts is something so common that it should be handled automatically.

Related issues (pinging some other people):

• https://github.com/glanceapp/glance/issues/106
• https://github.com/FreshRSS/Extensions/issues/234
• https://github.com/Ranchero-Software/NetNewsWire/issues/3975

[svilenmarkov]

No idea how you figured this out but thanks, this is the silver bullet I've been looking for!

I actually went ahead and inverted the property since I think the shorts being excluded is the desired outcome in the vast majority of cases.