Replace loader-utils with built-in webpack 5 functionality

[mydea]

Webpack has built-in types now, which seem to conflict with @types/loader-utils. I think we can just remove this dependency - see webpack/loader-utils#179.

Fixes #819

[mydea]

I rebased on latest master.

[rwjblue]

Kicked off CI

[chancancode]

We can't just remove the types. We currently use getOptions here. Removing the types package would cause the import itself to become a type error/any. Instead, I believe the recommendation was that we should remove the loader-utils package itself and switch from getOptions to using the (supposedly, I haven't verified) equivalent provided by webpack 5.

@mydea would you like to work on that?

[chancancode]

I think you can also address this while you are there. It seems like recent versions of webpack does have a type for LoaderContext, further, it takes a generic slot for the options so it could just be function hbsLoader(this: LoaderContext<HbsLoaderConfig>, ...) and this.getOptions() should Just Work™.

[mydea]

I will give it a try!

[mydea]

Hmm, does hbs-loader need to remain compatible with webpack 4? Meaning, do I need to build this in a way that it either uses the new webpack loader, or loader-utils, or can I update that package to webpack 5 and just use that?

I would go with the latter (@embroider/webpack relies on 5.x already anyhow), but if it should be the former I'm not sure what approach I should take to achieve that.

[mydea]

I updated the PR to update webpack peerDependency to 5 for hbs-loader, and replace loader-utils with the built-in functionality & the new types.

[ef4]

Thanks!