Refactoring: move all code files into a src directory

src/UI/Base/ToSvelte.svelte

@@ -0,0 +1,21 @@
+<script lang="ts">
+  import BaseUIElement from "../BaseUIElement.js"
+  import { onDestroy, onMount } from "svelte"
+
+  export let construct: BaseUIElement | (() => BaseUIElement)
+  let elem: HTMLElement
+  let html: HTMLElement
+  onMount(() => {
+    const uiElem = typeof construct === "function" ? construct() : construct
+    html = uiElem?.ConstructElement()
+    if (html !== undefined) {
+      elem.replaceWith(html)
+    }
+  })
+
+  onDestroy(() => {
+    html?.remove()
+  })
+</script>
+
+<span bind:this={elem} />