Overhaul webpack build

[daedalus28]

Our current build process means that we have to avoid using async/await in our actual source because it can cause regeneratorRuntime errors that, honestly, we don't fully understand.

It's led to insanity like #308 - which, while clever, leads to a terrible developer UX for contributors.

[chief10]

When does this happen @daedalus28 ? I added async/await back into the code to reproduce the error during the build process but wasn't able to.

[daedalus28]

Hi @chief10! The error doesn't happen during build time, it shows up when end users try to use the bundled code.

It may not be relevant, but the app we saw this issue on was using create-react-app specifically.