[FEAT] Webpack stats.json support

[tstackhouse]

Is your feature request related to a problem? Please describe.
It doesn't seem like we support the --statsJson option, setting that to true does not produce a stats.json file in dist/apps/<app> the same way that an app using e.g. the angualr devkit builder does.

Describe the solution you'd like
In build.impl.ts in the callback for the webpack process, we have access to the stats object, and can to stats.toJson("verbose") to get the data that a tool like webpack-bundle-analyzer can process.

Describe alternatives you've considered
I'm not sure there's any other good way to evaluate how the build process works and find ways to optimize. I know my use case is a bit unique, we have 70+ lambdas in one app and it results in relatively long builds, and I've actually had to use some custom forks of this library and serverless in order for it to work properly, and have been trying to remedy that now that I have time.

Check which provider is affected:
[] AWS
[] Azure
[] Google Cloud Platform

Check which framework is affected:
[] Angular
[] Nodejs
[x] Serverless
[] Lambda
[] Infrastructure as a code

Additional context
I'm planning on putting together a PR for this shortly, since it's relatively minor.

[wickstargazer]

hey we merged and published 1.1.1 but i saw another PR, do we need that to be merged as well?

[tstackhouse]

If you’re good with that PR, it would be awesome if we can get it in, we’ve been trying to get our project into the latest plug-in and serverless 2, but it’s a hefty app and was running into memory issues

[wickstargazer]

merged and published to 1.1.2

[tstackhouse]

Oh I see you were referring to #120, yes, that was definitely something to be merged (which I see is is merged and released now), as it was a bugfix for this PR.

I was referring to #121. I was on mobile so a long reply is hard to manage.