JS: Import maps support

[Silic0nS0ldier]

There is currently an import maps standard in development that may lend itself to JS/TS ecosystems. Support based on current concepts should be a fairly easy transition, but its worth keeping an eye on this.

https://wicg.github.io/import-maps/
https://github.com/WICG/import-maps
denoland/deno#2360

[Silic0nS0ldier]

Support has matured very well. At least where JS is concerned, this eliminates the need to mutate packages for path correction.

It may be possible to establish a convention for other files based on this.