workflows: make task state filter consistent with tree/table view

[oliver-sanders]

The workflows sidebar has filtering which covers workflow and task state filters.

However, it differs from other related filter controls in that:

• When filters are applied a number badge appears rather than the icon illuminating blue.
• The task state filter controls differ.
• The select/deselect buttons/functionality differs (see also task state filter: add select all button #2431).