Refactor CLI
Now we simply pass @parity/electron
a string[]
of flags to launch Parity with.
Next up: test some more & move getRemainingArgs to a separate module (and write some tests for it).
I noticed that --ws-interface and --ws-port are not passed to Parity when spawning the process; they're only used to connect to an existing process. I passed them down when spawning Parity, otherwise it's impossible to set those launch options (they're not part of remainingArgs).