Fix optional property quick info showing redundant '| undefined'

[sw1tch3roo]

Fixes #61954

[DanielRosenwasser]

I don't think this is the change I had in mind (or at least, it's not testing the right stuff). The specific thing I'm bringing up is about hovering over Options itself when hover verbosity is enabled. It's not about quick info on accesses of specific properties.

While it's true that I think we should only show ? and not introduce the undefined type in these cases, you'll notice on the issue that the property border has a strangely different type compared to color.

[typescript-bot]

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