This implementation uses a really basic WebView to update stats once
a second. In the future it might make more sense to both move the
details into LibWebView, and to create a native widget for each platform
to remove the overhead of having an extra WebView.
Now we will only load resources from $build/share/Lagom. On macOS, we
load from the bundle directory Contents/Resources instead. This
simplifies the commands and environment variables needed to execute
Ladybird from the build directory, and makes our install setup less
awkward for distributions and packagers.