UX+Refactoring: use side-drawer for menu, reorder menu structure

src/UI/Base/DrawerLeft.svelte

@@ -0,0 +1,20 @@
+<script lang="ts">
+  import { Drawer } from "flowbite-svelte"
+  import { sineIn } from "svelte/easing"
+  import { UIEventSource } from "../../Logic/UIEventSource.js"
+
+  export let shown: UIEventSource<boolean>;
+  let transitionParams = {
+    x: -320,
+    duration: 200,
+    easing: sineIn
+  };
+</script>
+
+
+<Drawer placement="left" transitionType="fly" transitionParams={transitionParams} hidden={!$shown} on:close={() => shown.set(false)}>
+  <slot>
+    CONTENTS
+  </slot>
+</Drawer>
+