Wrong calculation for `getRoundRect` stroke width

[victor-wm]

https://github.com/rdkcentral/Lightning/blob/master/src/tools/Tools.mjs#L55 defines the canvas width as w + strokeWidth + 2 but I think that was a mistake. The real size should have been w + strokeWidth * 2 instead.

[elsassph]

Actually I'm not sure it's wrong.

[elsassph]

Calculations are correct, but...

Left: element without w/h set
Right: element with w/h set (as passed to getRoundRect)

The problem is that when requesting a texture of a certain width/height, you don't actually get the requested size, but the size + stroke + 1... which means in a lot of places where we use this util, we create textures which get squeezed a bit and thus lose their quality.