PR 5868: Rename clip to clipBehavior in compositing.dart

PR 5973: Call drawPaint instead of drawPath if there’s clip

PR 5952: Call drawPath without clip if possible

PR 20205: Set default clipBehavior to Clip.none and update tests

PR 20538: Expose clipBehavior to more Material Buttons

PR 20751: Add customBorder to InkWell so it can clip ShapeBorder

PR 20752: Set the default clip to Clip.none again

PR 21012: Add default-no-clip tests to more buttons

PR 21703: Default clipBehavior of ClipRect to hardEdge

PR 21826: Missing default hardEdge clip for ClipRectLayer