feat: add cookie in request header

[babu-izhan-5001312]

Added Cookie field in Request Header as there is a need of sharing cURLs with the Cookie in the request.

[alexbrazier]

I'm not sure if I understand the reason behind this as wouldn't it be confusing to mix request headers with response headers?

If you need to copy the set-cookie header then you can use the "Share full request" button, but the format of set-cookie and cookie are different headers so I wouldn't have expected this to work in a curl request without modifying