Fix webtorrent, don't exclude dependencies

[dcposch]

Fixes #5849

Also lazy-load webtorrent-remote in the browser process.

• This should make startup a bit faster, since require('webtorrent-remote/server') will pull in webtorrent, which is a big module.
• It also makes exceptions like LSOpenURLsWithRole() failed with error -10810 on the packaged build #5849 easier to debug. Instead of getting a cryptic error, you get a stack trace at runtime when you try to load your first torrent URL.

BTW, I recommend:

• Measuring startup time. This can be as simple as adding a console.time ... console.timeEnd. We do that in WebTorrent Desktop and it helps catch performance regressions.
• Add a bit more error handling on startup. If the packaged app crashes on launch because of a require() error, it would be better to print the stacktrace than the LSOpenURLsWithRole exception.

[dcposch]

@feross @bbondy @luixxiul

[bbondy]

++

[luixxiul]

Should this fix #5855 too? @dcposch

[dcposch]

@luixxiul yes