Allow Merging polygons and lines

[thebiblelover7]

Is your feature request related to a problem? Please describe. After importing data from openstreetmap, I wanted to join two existing polygons into one. I wanted to remove the line between them, but I could not find a way to do so, and I wasn't able to find any similar feature request.

Describe the solution you'd like Allow selecting multiple polygons and add a button that allows them to be merged into one polygon. From this to this:

Describe alternatives you've considered Redrawing each polygon to be united would take a lot of time, especially when I have a lot of them. If snapping to nodes was available, that would make this a lot easier.