Add functionality that allows users to draw polygons to define analysis regions #2
Description
The functionality should allow users to create custom analysis regions by drawing arbitrary polygons directly on the echogram. Users should be able to select multiple points on the echogram to define the vertices of each polygon.
The drawn polygons should:
- Be editable (users can adjust or remove points as needed)
- Support multiple polygons within a single session
- Be exportable in a format compatible with the Region Browser (i.e., include polygon vertices and associated metadata such as the time range)