SWF-Editor: Export workflow to svg

[handreyrc]

Summary

The goal of this task is to add means to export the workflow to SVG.
A button should be added to the zoombar to export the workflow to SVG file.
An API should also be added to get the SVG content (string) without creating a file.

Description

React flow provide means to integrate external libs to do the job of exporting the canvas content to various formats.

• Integrate a suitable library to export the workflow to SVG.
• Add a button to the zoombar to export the workflow to SVG file.
• Add an API to export the workflow to SVG content so it can be retrieved in text format.

Testing

Run the component and load a valid workflow from storybook.
Click on the button to export to SVG and check the download file.
Open the console and call the API to get the SVG content for the workflow.