81012 Fix “LUCI console” link (team, cla: yes, waiting for tree to go green, documentation)

81706 Integrate MaterialBanner with the ScaffoldMessenger API (severe: new feature, framework, a: animation, f: material design, a: fidelity, cla: yes, d: api docs, d: examples, a: quality, waiting for tree to go green, documentation)

81884 Gesture recognizer cleanup (framework, cla: yes, d: api docs, a: quality, f: gestures, documentation)

81932 Add some examples of widgets that support visual density (framework, f: material design, cla: yes, d: api docs, waiting for tree to go green, documentation)