Remove substrate-in-the-browser (#9541)

* Comment out browser stuff

* Remove browser stuff

* Remove more wasm transport code

* Remove ExtTransport and rework how telemetry initialises.

* Change (most) wasm-timer using code to use std::time

* Rename CI-job

* Aura does not compile for wasm

* Remove testing in the browser on CI

* Update README

* Leave `StreamSink` be

* fmt