[Bug] Imports - resolved paths can be incorrect

When generating imports the path walker/resolver needs to cater for when the depth of the source file is e.g. deeper along the same tree as the current file, or vice versa.

See the FIXME in https://github.com/danielrob/aperitif-editor/blob/master/src/containers/EditorContainer/selectors/getCurrentFileImports.js

Open src/containers/EditorContainer/selectors/getCurrentFileImports.js and start at the referenced FIXME, tracing the path walker/resolver for source and current files at different depths in the same tree. Done means generated import paths remain correct when either file is deeper than the other.

Written by the indexing model from the issue text.