fix(cpn): QoL tweaks to joystick preferences (#3105)

* Add preference option to Companion to disable the 'Cannot open joystick, joystick disabled' popup warning when starting the simulator.

* Don't erase joystick settings if user opens preferences dialog while joystick is not connected.
Remove reference to "Ubuntu" font family for 'Radio Type' label in preferences dialog (generates warning on MacOS).

companion/src/simulation/simulatorwidget.cpp

@@ -691,7 +691,8 @@ void SimulatorWidget::setupJoysticks()
       joysticksEnabled = true;
     }
     else {
-      QMessageBox::critical(this, CPN_STR_TTL_WARNING, tr("Cannot open joystick, joystick disabled"));
+      if (!g.disableJoystickWarning())
+        QMessageBox::critical(this, CPN_STR_TTL_WARNING, tr("Cannot open joystick, joystick disabled"));
     }
   }
   else if (joystick) {