Change to groups and exposure of groups, add sticky header to first group item, fix shared questions

UI/Input/LengthInput.ts

@@ -45,6 +45,7 @@ export default class LengthInput extends InputElement<string> {
                 background: this.background,
                 allowMoving: false,
                 location: this._location,
+                attribution:true,
                 leafletOptions: {
                     tap: true
                 }