Add TourStep cover image

Author: snowe2010

client/packages/lowcoder/src/comps/comps/tourComp/tourComp.tsx

@@ -52,6 +52,7 @@ let TourBasicComp = (function() {
         arrow: step.arrow || true,
         placement: step.placement as PlacementType,
         mask: step.mask,
+        cover: step.cover ? (<img src={step.cover} />) : undefined,
         type: step.type || "default",
       };
     });

client/packages/lowcoder/src/comps/controls/tourStepControl.tsx

@@ -409,6 +409,7 @@ let TourStep = new MultiCompBuilder(
     placement: dropdownControl(PlacementOptions, "bottom"),
     hidden: BoolCodeControl,
     mask: MaskControl,
+    cover: StringControl,
     type: dropdownControl(TypeOptions, "default"),
   },
   (props) => props
@@ -438,6 +439,9 @@ TourStep = class extends TourStep implements TourStepCompProperty {
           label: "Arrow",
         })}
         {hiddenPropertyView(this.children)}
+        {this.children.cover.propertyView({
+          label: "Cover Image Url"
+        })}
         {this.children.mask.propertyView({
           label: "Mask",
           tooltip: TourStepMaskTooltip,