Use new ts-loader and compatible version of webpack-contrib

[maier49]

Type: bug

The following has been addressed in the PR:

• [x] There is a related issue
• [x] All code matches the style guide
• [ ] Unit or Functional tests are included in the PR

Description: This updates the version of ts-loader used, and uses the new onlyCompileBundledFiles option. As a result, errors in test files, or other files that are not included in the resulting bundle, will not fail dojo build. dojo build -w still does not rebuild when tests are built, but dojo build -w --with-tests does, and since test files no longer break dojo build -w that's ok.

The other changes are just fixing some weird formatting issues in webpack.config.ts, and updating to the next version of webpack-contrib (not released yet) that will fix an incompatibility between the css-module-dts-loader and the new version of ts-loader.

Resolves #227, #113

[maier49]

@matt-gadd Is this still something we'd like to land here or should it just wait for the new build command to be completed?

[matt-gadd]

@maier49 lets land this 👍