widgets/canvas library

1. node_program_editor package
2. documentation
3. widgets/canvas.dart

node_program_editor package

1. Libraries
2. actions
3. core/controller
4. core/painter
5. models/connection_model
6. models/node_data_model
7. models/node_models
8. models/port_model
9. models/selected_port_info_model
10. models/temp_link_model
11. node_program_editor
12. utils/jsonify_color
13. widgets/canvas
14. widgets/node