Add overlay option for retopology, which hides the shaded mesh akin to Hidden Wire, and offsets the edit mesh overlay towards the view.
Related Task #70267
Pull Request #104599
Previously [D16255](https://developer.blender.org/D16255)
There is no option to adjust the edge_width like there is in the preferences for vertex_size and face_dot_size.
I only added the option for 3DView and UV/Image Editor, and limited both to a max size of 5 pixel, since the edges do not look very nice with too high values.
In the UV Editor only, there are always black outlines on the edges, I could not find a way to reduce the increasing thickness of these black outlines.
The default edge_width of 1 pixel:
Here the edge_width with a falue of 3:
And here the visible increase of the dark border of the edges and their overlap (even at the maxed size of 5):
Lastly for the 3DView the max edge_width of 5 looks like this:
Pull Request #104741
Currently the passepartout color is hardcoded to black. While a
sensible default for cinema, it may make less sense for other media,
whether video, print, web, etc. It greatly affects viewing conditions
of the image and should be user selectable, much like painting
programs allow.
Pull Request #104486
