[sfnt] Support variable 'COLR' v1 `PaintVarRotate*`. * src/sfnt/ttcolr.c (FT_PaintFormat_Internal): New enumeration values `FT_COLR_PAINTFORMAT_INTERNAL_VAR_ROTATE` and `FT_COLR_PAINTFORMAT_INTERNAL_VAR_ROTATE_CENTER`. (read_paint): Handle new enumeration values.