Issues with Polygon

[mags612]

Some issues related to polygons:

1. Deleting a polygon doesn’t actually remove it from the plot—it’s still visible as a filter after deletion.
2. When creating a new polygon, any previously deleted polygons would reappear in the list.
3. Multiple polygons cannot be displayed.
4. The polygon’s zooming function do nott adjust to the plot's resolution. See below comparison (RM02 vs RM03)