[http] Add Parameter Decorator @cookie to Specify Cookie Parameters

[su8ru]

close #4739

This PR adds @cookie decorator to @typespec/http, to decorate parameters as cookie parameters.

• How to Decorate Parameters in Cookie? #4721

[su8ru]

I think that @cookie in the return type should be an implicit body (like @path and @query), but I haven't been able to find where this is implemented.
Added a check for isCookieParam() to isMetadata(), but properties with @cookie in the return type are ignored from the content of the response.

[timotheeguerin]

aren't cookies allowed in response(server asking client to set the following cookies) we might need to design and decide exactly what we want in those cases though

[su8ru]

aren't cookies allowed in response

I noticed that cookies can also be allowed or required in responses (e.g. in communication between servers).
This could cause problems if cookies cannot be set, so it might be better to be able to specify cookies in responses.

[timotheeguerin]

Thanks for the contribution this is awesome! I think there is a little design around the response cookies we'll want to sort out before we merge this but this looks great overall!

[timotheeguerin]

would be awesome if you could add some js doc comment to those new functions, we are in the process of documenting all our api

[timotheeguerin]

not asking you to do more work but just so you know this won't add support for it to openapi3 emitter if thats what you were looking for. Would need a few more changes in the packages/openapi3 pkg probably

[su8ru]

I tried it in local playground, and it works for me.
It seems there is no specific support for parameters in openapi3, so I think there is no need to add support.
I'll try to add some tests for openapi3 👀