84434 Add TooltipTriggerMode and provideTriggerFeedback to allow users to c… (severe: new feature, framework, f: material design, cla: yes, f: gestures, waiting for tree to go green)

84988 Adds mainAxisMargin property to RawScrollbar (severe: new feature, framework, f: scrolling, cla: yes, waiting for tree to go green)

85221 [new feature]introduce ScrollMetricsNotification (severe: new feature, framework, f: scrolling, cla: yes, waiting for tree to go green)

85338 Expose minThumbLength, crossAxisMargin, and minOverscrollLength on RawScrollbar (severe: new feature, framework, f: scrolling, cla: yes, waiting for tree to go green)