[Bug] import with relative file paths

[softmattertheory]

Describe the bug
The import keyword appears to be looking relative to the CWD, rather than the file path of the current file.

To Reproduce
The following folder structure and files illustrate the problem
/folder1/ a.morpho
/folder1/ b.morpho -> import "a.morpho"
/folder2/ c.morpho -> import "../b.morpho"
Running c.morpho yields an error that "a.morpho" could not be found.

Expected behavior
import should simply find and import the file.