Copy nested dependencies while generating nar executables

[h2non]

When creating nar executables, if the nar has not been installed as global dependency, it might fail due to missing shared dependencies, since the current strategy is to copy the whole directory.

The solution is resolving nested shared dependencies and copying them to the node_modules nar directory inside the executable tarball.

[h2non]

Create test case for intermediate shared dependencies.

[h2non]

Done!