fix(launcher): make dumpio and pipe options work together

[yury-s]

Don't ignore stdout and stderr when using pipe for remote debugging and dumpio is true. In that case puppeteer process connects to the stdout/stderr streams of the child process and it will not hang.

[aslushnikov]

Let's add a test! E.g. similar to https://github.com/GoogleChrome/puppeteer/blob/3982a603cc0db32bf05cd0960d24679a5c39313b/test/fixtures.spec.js#L25-L41

[yury-s]

Let's add a test!

@aslushnikov Done. I was originally inspired by testing approach from 14e69d1 :)

[aslushnikov]

Thanks!