Usersettings: use a collapsable dropdown, introduce dropdown special visualisation

src/UI/Popup/GroupedView.svelte

@@ -0,0 +1,27 @@
+<script lang="ts">
+  import type { SpecialVisualizationState } from "../SpecialVisualization"
+  import type { Feature } from "geojson"
+  import { UIEventSource } from "../../Logic/UIEventSource"
+  import type { OsmTags } from "../../Models/OsmFeature"
+  import LayerConfig from "../../Models/ThemeConfig/LayerConfig"
+  import AccordionSingle from "../Flowbite/AccordionSingle.svelte"
+  import SelectedElementView from "../BigComponents/SelectedElementView.svelte"
+  import TagRenderingAnswer from "./TagRendering/TagRenderingAnswer.svelte"
+
+  export let state: SpecialVisualizationState
+  export let selectedElement: Feature
+  export let tags: UIEventSource<OsmTags>
+  export let labels: string[]
+  export let header: string
+  export let layer: LayerConfig
+
+  let headerTr = layer.tagRenderings.find(tr => tr.id === header)
+
+</script>
+
+<AccordionSingle>
+  <div slot="header">
+    <TagRenderingAnswer {tags} {layer} config={headerTr} {state} {selectedElement} />
+  </div>
+  <SelectedElementView mustMatchLabels={new Set(labels)} {state} {layer} {tags} {selectedElement}/>
+</AccordionSingle>