Consider webpack again

[dschaefer]

We will be using webpack to bundle the webview contents (React and stuff). Microsoft is really pushing to have extensions themselves also built with webpack. Here is a sample from their samples repo:

https://github.com/Microsoft/vscode-extension-samples/tree/master/webpack-sample

I think it makes sense to play along. It also allows us to have a single build process for all contents of the extension using webpack.

[dschaefer]

We are now using webpack for the Memory Browser client side. I'm seeing some weird behavior in VS Code editing the project. Since we have to exclude the client source from the regular tsc build, the tsconfig.json has an exclude statement there. I looks like vscode picks that up and doesn't fully parse the client source, thus not picking up errors.

There are other ways to get around this than port everything to webpack so we can remove the exclude, of course.