Add the code for compiling node-cli for WASM-browser (#3974)

* Extract CLI to separate module in node/cli

* Make node/cli compile for WASM

* More work on node/cli browser

* More work on browser node

* More work

* More work

* Purge a bit the CI script

* More clean up

* Remove substrate-finality-grandpa from the CI

Its tests use tokio, which fails to compile.

* Address review

* Add rocksdb feature to the service

* Fix substrate-service WASM CI

* Apply suggestions from code review

Co-Authored-By: Bastian Köcher <bkchr@users.noreply.github.com>

* Don't WASM-compile substrate-service altogether