[JS] Move to npm ^8 and fix webpack config

[paulcam206]

Related Issue

Fixes #6634
Fixes #6635
Fixes #6636
Fixes #6637
Fixes #6638

Description

Kind of a large set of changes here -- it ended up being somewhat necessary to do all of these things at once in order to keep everything building/running correctly. The laundry list of changes:

• Move to npm ^8
  • ACTION REQUIRED: In order to continue to work with our NodeJS codebase, your npm instance needs to be updated (npm i -g npm@latest).
  • Aside from just keeping our codebase fresh, this also sets us up to investigate using workspaces as a lerna replacement
• Move to node ^14
  • I'm not sure if there's really any impact here, but you should update your local NodeJS install to a recent v14LTS build
  • We currently target NodeJS 10 or 12, but 14 is the current LTS release. It's worth noting that there really wasn't much in the way of change in our codebase here...
• Lift common dependencies to root project
  • This makes updating dependencies easier and makes npm i and npx lerna bootstrap faster
• Move everything over to webpack ^5
  • There were some places where we were using outdated ^4 versions
  • We also needed to finish the migration from ^4 everywhere -- various plugins we used weren't updated at the same time leading to deprecation warnings during builds
• Updated to the latest eslint and verified that rules work

How Verified

• local builds, spec generation, site spot check

Microsoft Reviewers: Open in CodeFlow

[ghost]

Hi @paulcam206. Thanks for helping make the AdaptiveCards JS renderer + tooling better. As additional verification, once the JS build succeeds, please go to the test site to test out your website/designer changes.

[licanhua]

I didn't see the workspace is replaced, and lerna is still used.

[paulcam206]

I didn't see the workspace is replaced, and lerna is still used.

As noted in the description:

Aside from just keeping our codebase fresh, this also sets us up to investigate using workspaces as a lerna replacement

This PR gets us ready to evaluate moving, but I didn't want to muddy this PR with those changes (should they be feasible). The investigation for workspaces is being tracked in #6481

[beervoley]

LGTM :)