Improve Fritzing part editor for through-hole drilling (THT components)

[greenhilldev]

Problem

The following description reflects fritzing's part editor, mainly the PCB view:
Upon SVG import, the part editor checks the SVG file for proper named layers, but it does not check the given xml element names inside the SVG.
When importing a SVG file for PCB view, the xml element name for the part's holes (drills) can be named as "ellipse" and then set to THT inside the part editor. Fritzing is showing the part correctly!
This will run into an error later when it comes to production, because (some) gerber viewers do not perform drills for holes which are described as "ellipse" inside the svg. They insist on a proper identification as "circle" , which seems fully logical.
Fritzing: 0.9.4. on macOS Catalina

Side Note

When exporting a PCB view out of Inkscape as an SVG (Inkscape is referenced in most tutorials about fritzing part creation) all drawn circles might not be defined as "circle", most likely they are defined as "ellipse" with rx and ry having nearly the same value.

Proposed Solution

The fritzing part editor could throw a warning when the imported SVG file contains xml elements which are named "ellipse" and the user tries to set them to THT.