This was originally written by Ankit Meel as a GSoC 2020 project. Howard Trickey added some tests and made some corrections/modifications. See D13046 for more details. This commit inserts a new menu item into the export menu called "Wavefront OBJ (.obj) - New". For now the old Python exporter remains in the menu, along with the Python importer, but we plan to remove it soon (leaving the old addon bundled with Blender but not enabled by default).