[FR] Allow menu bar only mode for macOS

[rusmux]

Feature description

When I close the app, it stays in the dock:

However, connecting and opening the dashboard is done in the menu bar:

There is no need to keep the app in the dock, especially since even if you click on it, it will not open the dashboard. For me right now, it just clutters up the space. I like the way it's done in the WireGuard client, where the application appears in the dock only when the dashboard is opened.

Thank you!