Add Missing API: HttpCapabilitiesBase.Cookies

## Summary

provides the value if the browser supports cookies.

## Motivation and goals

HttpCapabilitiesBase.Cookies provides the value if the browser supports cookies. But it is not in adapters yet.

## In scope

HttpCapabilitiesBase.Cookies

## Examples
```C#
if (!context.Request.Browser.Cookies)
    return;
SetResponseCookie(context);
```
