D3 examples should not use fixed width

```

var d3 = require(['d3'], function (d3) {

var width = 600,
height = 500;
```

should get width from the notebook.
ideally the output would have a thumb to resize it https://github.com/twosigma/beakerx/issues/4857
but at least, it should not be a constant.

Locate the D3 examples referenced by the issue and inspect how their notebook output dimensions are set. Compare the fixed width in the shown snippet with the notebook-provided width; done means the examples no longer use a constant width and render at the notebook width. The optional resize thumbnail is described in issue 4857 and is separate from the minimum request.

Written by the indexing model from the issue text.