Disable chunking to prevent importScripts calls in web

[joyceerhl]

This PR fixes #155225

[lramos15]

@alexdima @jrieken Do you think this is an acceptable fix for avoiding importScripts or is there possibly some perf issues here? By disabling chunks this prevents webPack from possibly placing modules in separate files and then trying to use importScripts. This was happening some reason to the telemetry modules. @joyceerhl and I are not webpack experts so are unsure if you know of any negative side effects here

[jrieken]

It's the trade-off between loading all code at once (and thereby loading too much for getting started) and loading code in chunks as needed (and thereby having the potential for intermittent "pauses"). VS Code itself loads all its code at once, around 10MB, and that's still OK. Extensions are usually much smaller so I don't believe this is an issue. Also, for the web worker extension host it is not possible to lazily fetch more modules - so it is not that you have choice here.

(*) the problem with the extension host is that extension code calls require('vscode') and that in nodejs we have good way to intercept that. The call doesn't return a JS module but an instance of our API. For that we intercept the call (which we could do in the web) but we also need to know the file that's making the call. The latter is only possible with stack inspection in the web and that isn't the best way of doing it