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

[su8ru]

close #4739

• @typespec/http
  • add @cookie decorator to decorate parameters as cookie parameters
  • add response-cookie-not-supported diagnostics
    • to be emitted when response cookies are specified
  • add tests for cookie params
• @typespec/http-server-javascript
  • throw UnimplementedError when cookie params came
• @typespec/openapi3
  • support cookie param case
  • add tests for cookie params

response cookie design

in	explicit body	implicit body
diagnostics	metadata-ignored	response-cookie-not-supported
result	included (unified with other metadata)	NOT included (prevent breaking change for set-cookie)

---

based on:

• 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]

/azp run typespec - pr tools

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[su8ru]

I ran pnpm change add and added the changelog... is this correct? This is my first time 😟

[su8ru]

@timotheeguerin Hi, CI issues solved. Could you take a look? Thanks!

[timotheeguerin]

Hi @su8ru the PR looks great, we just need to confirm thats exactly what we want to do before merging. I believe this should make it for next release(early november).

[timotheeguerin]

Thanks again @su8ru for the contribution!!

[su8ru]

(why conflicted...? and does it resolved...?)

[timotheeguerin]

(why conflicted...? and does it resolved...?)

yeah we have been reorganizating the docs, sorry I meant to go fix the conflict in your branch after I tried to merge it and forgot.