Revisit namespaces and modules refactoring

[hurricup]

I can swear it was an issue about refactoring packages files, because it's was a mess. But i can't find it and not sure how it works right now.

The problem on implementation phase was - unclear how to handle changing namespaces and related files which should be renamed or moved or whatsoever.

We need a clear view on this.

There are basically 3 cases:

1. Renaming namespace.

• it could involve renaming or moving a module file with the same name. Which could contain other namespaces (should they be removed?)

2. Renaming module.

• it could involve renaming of nested namespaces. And may involve moving files. Should we just invoke move action instead of rename refactoring?

3. Renaming or moving a file or directory containing modules and therefore namespaces.

• Should we adjust all things inside? With what logic?

We should probably just implement and test all simple cases and then populate them with additional logic.