"Interactive input" via clicking stage button similar as in pipeline diagram

If there is interactive input (i.e. Pipeline: Input Step), then the stage button has different color (or form) and the button becomes "clickable".

User can select an option in Aggregator View Plugin, if there is interactive input.

Note: if the feature is complex, we can break it into two tasks:

• button visualization when interactive input exists
• interactive input in Pipeline Aggregator View