68327 InteractiveViewer constrained docs (cla: yes, framework, waiting for tree to go green)

68358 [SwitchListTile and CheckboxListTile] Adds selectedTileColor property (cla: yes, f: material design, framework, waiting for tree to go green)

68374 Fix links to GitHub bug template (a: internationalization, cla: yes, framework, waiting for tree to go green)

68402 Fix error cursor position for left and right arrow event after text selection (cla: yes, framework, waiting for tree to go green)

68494 InteractiveViewer minScale docs improvement (cla: yes, framework, waiting for tree to go green)

68505 Updated one reference to FlatButton in real_tests/extension_test.dart (a: tests, cla: yes, framework)