For element-hq/element-web#10524

Upgrading to babel 7 gets a lot of the compilation stuff for free. The major changes we care about are:
* The packages are now namespaced (hence all the package changes)
* We use the `env` preset instead of the long-since deprecated es20XX packages. 
* Added `--verbose` to maintain log output from the previous version.

This also meant fixing `ScalarAuthClient`: we can no longer mix `module.exports` and `import` in the same file. 

The SdkConfig was converted to TypeScript to prove this works (it does).

The update isn't super required, but it does help fix some of the module problems. We have to export ourselves as commonjs to make the tests happy, and empirically riot-web's webpack is also happy with this. 

The changes to the karma preprocessors is to ensure the app bootstraps correctly.

This makes the app happy.