Add GUI controls to create points, lines, and polygons, just like how it is done in Apple keynotes or Microsoft PowerPoints.
- All GUI controls need corresponding menu item.
- All GUI controls and menu items need corresponding Python API to call from the interactive terminal.
- Separate control from operations. Geometrical operations do not need to depend on Qt and can be tested without it.
Add GUI controls to create points, lines, and polygons, just like how it is done in Apple keynotes or Microsoft PowerPoints.