Is your feature request related to a problem?

ESP WebSocket-client instances are unable to use cookie-based sticky sessions, because there is no interface to extract the upgrade response headers.

Here's an example of what we'd like to use: https://docs.aws.amazon.com/prescriptive-guidance/latest/load-balancer-stickiness/alb-cookies-stickiness.html, which tries to set lb_cookie to remember which backend server the device connected to, but there's no way for the client to read the value of the Set-Cookie: lb_cookie=<server-index-value> header.

Describe the solution you'd like.

When connecting, I'd like the ability to iterate HTTP response headers during the WEBSOCKET_EVENT_CONNECTED event handler.

Once I have this, I can save out the lb_cookie for use in future reconnections.

Describe alternatives you've considered.

No response

Additional context.

No response