Add bounding box calculation and visualization in BoundingBoxTest

[frankvp11]

This adds the ability to access the bounding boxes of shapes in GraphicSVG.
The Text case isn't perfect, mostly because the exact character size is unknown.
Let me know if there are any issues. This is what the test looks like:

[frankvp11]

Found edge case of repeated rotations like this:

                    , roundedRect 40 20 5
                        |> filled green
                        -- |> skew 0.5 0
                        |> rotate (degrees 30)
                        |> rotate (degrees -30)
                        |> move (0, 40)
                       ```
Looking to fix now

[frankvp11]

One of the things that I've learned is that you should inspect the element if it doesn't appear like its' correct.
For example, if we look at this test case:

It doesn't appear correct without inspecting it.
Same thing goes for this test case:

I've updated the PR and it works better now.