Move marker property from BaseWidget to SliderWidget (#584)

* Move marker property from BaseWidget to SliderWidget

* nit

src/widgets/BaseWidget.ts

@@ -7,9 +7,7 @@ import type { IBaseWidget, IWidget, IWidgetOptions, TWidgetType, TWidgetValue }
 export abstract class BaseWidget implements IBaseWidget {
   linkedWidgets?: IWidget[]
   options: IWidgetOptions<unknown>
-  marker?: number
   label?: string
-  clicked?: boolean
   name?: string
   type?: TWidgetType
   value?: TWidgetValue

src/widgets/SliderWidget.ts

@@ -10,12 +10,14 @@ export class SliderWidget extends BaseWidget implements ISliderWidget {
   declare type: "slider"
   declare value: number
   declare options: IWidgetSliderOptions
+  marker?: number
 
   constructor(widget: ISliderWidget) {
     super(widget)
     this.type = "slider"
     this.value = widget.value
     this.options = widget.options
+    this.marker = widget.marker
   }
 
   /**