Use Menu Extra Icon instead of Dock Icon

[PotatoFi]

Is your feature request related to a problem? Please describe.
Usually, "background" applications in macOS use a Menu Extra icon (an icon near the clock on the menubar, like the Wi-Fi or Bluetooth icons) instead of a full icon in the dock. CameraLive requires minimal interaction to use - once it's running, there's usually no need to access it again.

Describe the solution you'd like
Instead of showing a full icon in the dock, use a black-and-white Menu Extra icon.