Allow access to the workflow state object in hook_preprocess_views_view_field

Motivation

I wanted to add an additional markup to the output of the current_state field, and I noticed that only the state's label is available in hook_preprocess_views_view_field hook context.

Steps to reproduce

Create a view with current_state_views_field in there, then implement hook_preprocess_views_view_field hook, check that there's no additional data in $variables['field']

Proposed resolution

Store the current state object in an attribute of current_state_views_field object