[D&D] Save Visualization

[ashwin-pc]

Add the ability to save and restore a visualization using the drag and drop editor

Tasks

Saving

• [x] #1878
• [x] #1879
• [ ] #1880

Loading

• [x] #1868
• [x] #1867
• [ ] #1881
• [x] #1882
• [x] #1887

Management

• [x] #1817
• [ ] #1883

Testing

• [ ] #1884
• [ ] #1885