PieTouchData is missing simple "button pressed"-type gesture

[chris-rutkowski]

PieTouchData in pie chart, has touchCallback property which contains FlTouchEvent (and response).

That event is of multiple types gesture, pan, up/down, drag, long press up down...

The event has a property isInterestedForInteractions, but many of events have the value true there. When PieChart is displayed on the scrollable view, user attempting to scroll the screen, touching the chart is firing those events with falsely assumed interested for interactions.

I sincerely believe most of us need to handle button-press like event - touch and release the finger without significant movement.
Could we have a easier callback?

Cherry on the top. That callback contains a PieTouchResponse, which has a nullable section, which can have a -1 index. Wouldn't it be simpler, to have a callback directly in PieChartSectionData object?