Feature Request: Respect package.json alias section when resolving dependencies

[schlichtanders]

As discussed in #2564 current jspm is not able to treat alias definitions correctly.

It would be best, if jspm simply respects the alias definition from package.json so that the npm dependencies and the jspm dependencies match each other.

Importantly, alias my be such that a package on the one hand is aliased to a subpackage on the other hand. Or package to package, or subpackage to subpackage.

For instance for preact the alias section of package.json looks like

"alias": {
    "react": "preact/compat",
    "react-dom/test-utils": "preact/test-utils",
    "react-dom": "preact/compat",
    "react/jsx-runtime": "preact/jsx-runtime"
  }