Add client setting to enable shared order group window for single vehicles

src/table/settings.ini

@@ -45,6 +45,7 @@ static bool MaxVehiclesChanged(int32 p1);
 static bool ImprovedBreakdownsSettingChanged(int32 p1);
 static bool DayLengthChanged(int32 p1);
 static bool SimulatedWormholeSignalsChanged(int32 p1);
+static bool EnableSingleVehSharedOrderGuiChanged(int32 p1);
 
 #ifdef ENABLE_NETWORK
 static bool UpdateClientName(int32 p1);
@@ -4089,6 +4090,15 @@ strhelp  = STR_CONFIG_SETTING_SHOW_ADV_TRACE_RESTRICT_FEATURES_HELPTEXT
 proc     = RedrawScreen
 cat      = SC_EXPERT
 
+[SDTC_BOOL]
+var      = gui.enable_single_veh_shared_order_gui
+flags    = SLF_NOT_IN_SAVE | SLF_NO_NETWORK_SYNC
+def      = false
+str      = STR_CONFIG_SETTING_ENABLE_SINGLE_VEH_SHARED_ORDER_GUI
+strhelp  = STR_CONFIG_SETTING_ENABLE_SINGLE_VEH_SHARED_ORDER_GUI_HELPTEXT
+proc     = EnableSingleVehSharedOrderGuiChanged
+cat      = SC_EXPERT
+
 ; For the dedicated build we'll enable dates in logs by default.
 [SDTC_BOOL]
 ifdef    = DEDICATED