Add `background` argument to `draw` function

[jofrevalles]

Currently, the draw function draws the circuit in color black without drawing the background. This may cause problems if the user is working in an environment with a dark background color.

As an example, here is a drawing inside VS Code using the color theme Dark+ (default light):

A straightforward solution would be to create an optional argument to draw function in which we could specify the background color of the output.