Hacky attempt at reinstating browser support map support

[pe8ter]

For the time being, this PR is here for support.

This PR is an attempt to reinstate browser-support-map-support.js back into this fork. Since this library overrides attempts to load the upstream version of the source-map-support library, consumers are broken because they rely on the existence of this file. We would like this fork to include this file once again.

Here you can see that there are several instances of this fork assuming the execution context is Node.js. There must be checks for the browser to stop this assumption.

Although there are no errors within in this library in particular, the dependency @cspotcode/soure-map-consumer still makes this assumption, particularly here.

Other things missing:

• This PR does not minify the built library because the minified file comes back from the Google service as nearly empty.
• No attempts to fix the various tests has been made. They are still broken.

[pe8ter]

I cannot commit to working on this. In the meantime, I'll convert my Karma config back to plain JavaScript so that ts-node does not impede loading the upstream version of this library.