Replace source-map with @jridgewell/trace-mapping

[onigoetz]

The trace-mapping module is faster than source-map in every benchmark https://github.com/jridgewell/trace-mapping#benchmarks

It's also being adopted by many packages across the ecosystem (Jest, Babel, Terser at least have included it already) And it doesn't need to be async like source-map 0.7.*

This would replace #286 and #206

Regarding the changes in this PR

• This project seems to have a wide compatibility with older Node.js versions, is that still needed ?
• I tested the changes with the browsers tests but they failed, but I also tested /without/ my changes and it still failed (on Firefox, does it only work on some browsers ? )

[SimenB]

@LinusU thoughts on this? 🙂