Using the path edit tool on one of the corners of a raster image breaks the graph

[redweasel]

To reproduce:

• Paste a raster image
• Select the path tool
• Click and drag on the image (can often happen accidentally)
• Observe that the node graph has an error.

This is a bug, since the tooling should avoid breaking the graph as part of #2214

[KartikSharma0]

I'm interested in working on this bug, what is the expected behavior when clicking and dragging an image using the path tool?

[Keavon]

There simply should be no path geometry corners to be clicked and dragged at all by the Path tool.

[Keavon]

Resolved by #3727.