Part of #116901. Avoid the "extractor" abstraction for creation of edit mode overlay data vertex buffers. Use threading::parallel_for loops instead. Also prefer code duplication over linking things that are unrelated. This is the last "extractor" loop that runs by default in edit mode so there is a small performance improvement there. Besides that, the changes is the same as the other similar refactors. Pull Request: https://projects.blender.org/blender/blender/pulls/122386