WebSocket AsyncAPI generation

[Bhashinee]

Description:
This is to track the improvements that we need to make for the current implementation.

• [1] Need to move the pipe code to the WebSocket module and use it in the client generation.
• [2] Remove doc warnings of the generated client.
• [3] Dispatcher stream id - When dispatcherStreamId is a required field, the user needs to provide a dummy value for it before the client replaces it with the actual value. The solution that we came across was to have an open record without the dispatcher stream ID field if it is present in the AsyncAPI spec.
• Implement dispatcher stream id in the WebSocket protocol. (Implement dispatcher stream id in the WebSocket protocol. #6757)

[Bhashinee]

We are not going to implement the first one as it was discussed to add the pipe module as a library.
Dispatcher streamID is implemented in ballerina-platform/module-ballerina-websocket#1367