Removed duplicity between t->mouse.center and t->center2d. Using always t->center2d
The diff assumes saving center2d on transform, instead of saving it under transform/mouse/center. I did in this way becuse the center is more related to transform than mouse input, but maybe is better to save 2D data under mouse
Of course duplicating variables about isn't great, since it can cause confusion or problems if their values diverge,
but the tradeoff is t->mouse is no longer self contained struct we can use on its own.
If we have to pass TransInfo into functions it means the mouse-input functions, they can access everything, scene/object.... etc.
So in this case I rather just have both t->center2d and mouse.center and leave this part of the code as-is.