Box layout algorithm interferes with set minumum size
```
node n {
	algorithm:box
	minimalNodeSize:"(60.0,60.0)"
	elk.padding:"[top=25.0,left=25.0,bottom=0.0,right=0.0]"
	node ni {
		layout[size:10,10]
	}
}
```
Drawing this graph I would expect a parent node with size 60x60 and a node inside that with a padding of 25 from the top left, putting it in the center of the 60x60 parent node.
Instead, a 35*35 node is drawn with the inner node locked in the bottom right corner.

I tracked down where this issue comes from and found [this commit](https://github.com/eclipse/elk/commit/89caa5cd53bf6a2a51534281f16702cb12cb82d1). In there, the BoxLayoutProvider was changed to not read the individual width and height and work on local copies of that, but change the x and y values of the instance stored in the minimum node size property directly. That causes the minimum size constraint to get messed with during box layout if a padding is configured. That should not happen.
The version previous to that commit looks good to me, or just to not put the values for the box layouter back into the bounds instance.