fix(macos): resolve ffmpeg export memory crashes and macOS desktopCapturer permission blocks#474

designedbyalok wants to merge 1 commit intosiddharthvaddem:mainsiddharthvaddem/openscreen:mainfrom

designedbyalok:fix-macos-fallback-uidesignedbyalok/openscreen:fix-macos-fallback-uiCopy head branch name to clipboard