VLC macOS interface redesign

The VideoLAN UI has been updated many times in the last years, now targeting 4.0 as the next major release. Previous GSoC projects have started updating the interface since 2012. With successive projects in 2017, 2018, and 2021. I want to build on their work, and keep refining the MacOS interface. This project consists of ironing out details and bugs that work toward the 4.0 milestone. I am basing myself off the issues open on Gitlab, but I am open to follow the direction the mentors find fit.