refactor(optimizer): split stream key and unique key

[st1page]

Currently, we have the pub fn logical_pk() method on plan Node.
But now we find stream_key is a very special concept, so we need to clarify here.
finally, we will have two different method

pub fn stream_key(&self) -> Option<&[usize]>;
pub fn unqiue_key(&self) -> Vec<Vec<usize>>;

[BugenZhao]

Related #9375

[github-actions]

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