Fix threads cache

[lukellmann]

This PR fixes a bug that threads weren't cached when receiving Guild events.
It also deprecates Guild.threads (it does not behave like one might expect) and instead replaces it with GuildBehavior.cachedThreads.

[HopeBaron]

Is there a way we could get these through rest?
if so we'd go with transforming this into a function that accepts a supplier

[lukellmann]

Is there a way we could get these through rest?
if so we'd go with transforming this into a function that accepts a supplier

You can only get active threads for a guild (and the activeThreads property already exists). To also get archived ones, you would have to request them for every channel individually, which we probably shouldn't do.
https://discord.com/developers/docs/topics/threads#enumerating-threads

[HopeBaron]

your primary concern is weather you can cache it from gateway or not; it's up to the user to do it.

[lukellmann]

What exactly does this mean for this PR?

[HopeBaron]

Looking back at this this looks just fine

[lukellmann]

Can be merged then?

[gdude2002]

Would be great to see a merge for this

[gdude2002]

Thanks o7