Split JS and JVM to allow independant updates

[mcarleio]

For future work it might be helpful to split the library between JS and JVM. This would allow to update them independently (and therefore faster) when a new kotlin version is released.

Background:

I wanted to do a PR to update to kotlin compiler 1.9.0. But I could not succeed, as there were problems with the JS part. I then tried to split JVM and JS parts in separate modules, but they seem to be quite mixed and I could not find an "easy" solution without changing to much.