wrap window.WebSocket to enhance network capture

[pauldambra]

Feature request

websocket implementations rely on window.WebSocket not window.fetch so our network capture doesn't see or report on websocket requests

if we also patched websockets then we could capture info about them too

to-do

• resurrect the ability to load different recorder.js versions
• add mechanism for letting decide roll those out by team id
• split xhr/fetch capture out of recorder.js
• add a web socket example in the playground
• add web socket wrapper
• make new recorder-v3.js that includes xhr/fetch/web socket capture
• figure out some UI for showing it in the network capture panel
• roll that out for some testers

Debug info

- [ ] PostHog Cloud, Debug information: [please copy/paste from https://us.posthog.com/settings/project-details#variables]
- [ ] PostHog Hobby self-hosted with `docker compose`, version/commit: [please provide]
- [ ] PostHog self-hosted with Kubernetes (deprecated, see [`Sunsetting Kubernetes support`](https://posthog.com/blog/sunsetting-helm-support-posthog)), version/commit: [please provide]

[mattc]

The individual messages inside the Websocket are conceptually equivalent to fetch calls, so that's what really needs to be captured.

The browser API for Websockets is very small. The minimal wrapping for capturing messages would involve patching the window.Websocket constructor, the send method (outgoing messages), and the message flavor of addEventListener (incoming messages).

Also consider tracking connection state/errors by monitoring the close method and the close/error/open addEventListeners.