Add setting for whether to show vehicle running costs per calendar year

See #660

src/table/settings/gui_settings.ini

@@ -1619,6 +1619,14 @@ str      = STR_CONFIG_SHOW_RAIL_POLYLINE_TOOL
 strhelp  = STR_CONFIG_SHOW_RAIL_POLYLINE_TOOL_HELPTEXT
 post_cb  = [](auto) { InvalidateWindowData(WC_BUILD_TOOLBAR, TRANSPORT_RAIL); }
 
+[SDTC_BOOL]
+var      = gui.show_running_costs_calendar_year
+flags    = SF_NOT_IN_SAVE | SF_NO_NETWORK_SYNC | SF_PATCH
+def      = false
+str      = STR_CONFIG_SHOW_VEHICLE_RUNNING_COSTS_CALENDAR_YEAR
+strhelp  = STR_CONFIG_SHOW_VEHICLE_RUNNING_COSTS_CALENDAR_YEAR_HELPTEXT
+post_cb  = [](auto) { MarkWholeScreenDirty(); }
+
 ; For the dedicated build we'll enable dates in logs by default.
 [SDTC_BOOL]
 ifdef    = DEDICATED