Update UX WorkflowStateListBuilder code

Problem/Motivation

When reviewing the WorkflowStateListBuilder State overview on the page /admin/config/workflow/workflow/MY_WORKFLOW/states, some change were made:
- add a separate column for the Drag handler; handler and State Label were in one column, but were not aligned. (Handler column can now still be a bit smaller, but I do not know how to do this.)
- The Creation State is not Draggable.
- Technically: the code is more left-aligned, escaping early from the functions.