Fix pygame.sprite.Group.has() behavior for no sprites given

[aatle]

Make Group.has() return True instead of False when no sprites (empty list, no arguments, etc.) are given.

Closes #2993

This is potentially a breaking change. Might not get approved. See issue for discussion.

[oddbookworm]

Can you motivate this change with an example of when this change would actually matter? Offhand, I can't come up with a valid use-case where it should matter what this returns if no sprites are passed

[aatle]

Sure.
I'll post it in the issue.

[ankith26]

I agree that this change is logical, but also, as pointed out before, it could be a backwards incompatible change that could break someones usage.

[MyreMylar]

I agree this makes sense, but I think this should wait for compatibility breaking release before being merged as the current behaviour has probably been around since the sprite group was created.

[ankith26]

Thanks for the PR!

Essentially this PR has my approval as well, I'm just drafting it for now because it cannot be merged right now for reasons Myre stated.