Update to upstream tinywl

- Use `Scene Graph` for rendering - Use golang `container/list` for toplevels - Follow upstream implementation as close as possible - Include all upstream comments to the code - Add more upstream protocol methods to `go-wlroots` lib - Separate wlroots API to the same structure as upstream - Use slog for logging (tint will be used when fixed in upstream https://github.com/lmittmann/tint/issues/55) - Closes #17