Based on recent developers feedbacks that needed to use props types
in order to wrap the lib's component they were stuck because we were
not exporting all of them.
Fixes#143
Adding this new variant makes necessary to reorganize the files to keep
a clear separations of concerns. As of now Select/index.tsx is just an
entrypoint to render either the mono or multi variant of the select.
Based on recent feedbacks this feature was needed. It is important for
the label to still be accessible to screen readers, that's why we
introduced the offscreen class.
Resolve#60
