Create a Postman collection for all Websocket actions

[tomtitherington]

Background & Scope

Create a collection for all the actions that can be taken with the Websocket handlers.

Proposed Changes

• Create a Postman Websockets collection with all the valid handlers and actions that the server exposes.
• Ensure that socket connection and terminate is included in the collection.
• Export this as JSON and check this into version control.

Additional Information

Exporting data in Postman documentation.