Refactoring: port "statisticsGUI" to svelte

src/UI/Statistics/SingleStat.svelte

@@ -0,0 +1,56 @@
+<script lang="ts">
+
+  /**
+   * Shows the statistics for a single item
+   */
+  import TagRenderingConfig from "../../Models/ThemeConfig/TagRenderingConfig"
+  import ToSvelte from "../Base/ToSvelte.svelte"
+  import TagRenderingChart, { StackedRenderingChart } from "../BigComponents/TagRenderingChart"
+  import { ChangesetsOverview } from "./ChangesetsOverview"
+
+  export let overview: ChangesetsOverview
+  export let diffInDays: number
+  export let tr: TagRenderingConfig
+
+  let total: number = undefined
+  if (tr.freeform?.key !== undefined) {
+    total = new Set(
+      overview._meta.map((f) => f.properties[tr.freeform.key])
+    ).size
+  }
+</script>
+
+{#if total > 1}
+  {total} unique values
+{/if}
+<h3>By number of changesets</h3>
+
+<div class="flex">
+
+  <ToSvelte construct={ new TagRenderingChart(overview._meta, tr, {
+  groupToOtherCutoff:
+  total > 50 ? 25 : total > 10 ? 3 : 0,
+  chartstyle: "width: 24rem; height: 24rem",
+  chartType: "doughnut",
+  sort: true,
+})} />
+</div>
+
+
+<ToSvelte construct={new StackedRenderingChart(tr, overview._meta, {
+  period: diffInDays <= 367 ? "day" : "month",
+  groupToOtherCutoff:
+  total > 50 ? 25 : total > 10 ? 3 : 0,
+})} />
+
+
+<h3>By number of modifications</h3>
+<ToSvelte construct={    new StackedRenderingChart(    tr,    overview._meta,
+      {
+        period: diffInDays <= 367 ? "day" : "month",
+        groupToOtherCutoff: total > 50 ? 10 : 0,
+        sumFields: ChangesetsOverview. valuesToSum,
+      }
+     )} />
+
+