Use same import path spec as node

[jeroen]

Currently we always assume the import statements are always paths relative to the working dir. However in the case of submodules, the import statement is relative to the parent module path.

Also if a path does not start with ./ it is probably under node_modules but not sure if we want to support that

Here are some details on path resolving: https://github.com/browserify/browserify?tab=readme-ov-file#example