Fix `FAILURE Library file 'microevent.ts' not found.` when setting libsFolder in matchstisk.yaml

[dimitrovmaksim]

The AS compiler's --lib option can't work with relative paths that go backward, e.g ../ or ../../ currently to fix that, users have to configure an absolute path in matchstick.yaml. This PR converts the libs path to an absolute path to handle this issue, so users can define both absolute paths and relative paths in the matchstick config