Refactoring: move all code files into a src directory

src/UI/Base/FloatOver.svelte

@@ -0,0 +1,38 @@
+<script lang="ts">
+  import { createEventDispatcher } from "svelte"
+  import { XCircleIcon } from "@rgossiaux/svelte-heroicons/solid"
+
+  /**
+   * The slotted element will be shown on top, with a lower-opacity border
+   */
+  const dispatch = createEventDispatcher<{ close }>()
+</script>
+
+<div
+  class="absolute top-0 right-0 h-screen w-screen p-4 md:p-6"
+  style="background-color: #00000088"
+>
+  <div class="content normal-background">
+    <div class="h-full rounded-xl">
+      <slot />
+    </div>
+    <slot name="close-button">
+      <!-- The close button is placed _after_ the default slot in order to always paint it on top -->
+      <div
+        class="absolute right-10 top-10 h-8 w-8 cursor-pointer"
+        on:click={() => dispatch("close")}
+      >
+        <XCircleIcon />
+      </div>
+    </slot>
+  </div>
+</div>
+
+<style>
+  .content {
+    height: calc(100vh - 2rem);
+    border-radius: 0.5rem;
+    overflow-x: auto;
+    box-shadow: 0 0 1rem #00000088;
+  }
+</style>