Please summarize your feature request

Cookie struct to support Partitioned property

Describe the functionality you're seeking in more detail

Hey Vapor team, the Cookie implementation doesn't have the Partitioned property. I can work on this issue if you want.

Have you considered any alternatives?

I can serialize the cookie and append the Partitioned string to it, but I think it would be better to support the Partitioned property. Like I said before, I can work on this issue if you want.