Add tests for MoonrakerSocketManager, some UI changes in front-end

Soyuz/Views/PrinterConfigView.swift

@@ -38,7 +38,7 @@ struct PrinterConfigView: View {
                                 printerManager.connectToBonjourEndpoint(result.endpoint)
                             } label: {
                                 Text("Connect")
-                                    .foregroundColor(.white)
+                                    //.foregroundColor(.white)
                                     .padding()
                             }
                         }

Soyuz/Views/SoyuzMenuBarExtraView.swift

@@ -83,7 +83,7 @@ struct SoyuzMenuBarExtraView: View {
                 openWindow(id: "soyuz_cfg")
             } label: {
                 Text("Printers")
-                    .foregroundColor(.white)
+                    .foregroundColor(Color("ButtonForegroundColor"))
             }
             Spacer()
             if(printerManager.isConnected) {