ui: New button to expand resolution text in a large modal

frontend/ui/src/lib/components/ResolutionModal.svelte

@@ -0,0 +1,26 @@
+<script>
+ import {
+     Icon,
+     Modal,
+     ModalBody,
+     ModalHeader
+ } from 'sveltestrap';
+ const toggle = () => (open = !open);
+
+ export let exercice = null;
+ export let open = false;
+ export let resolution;
+</script>
+
+<Modal isOpen={open} {toggle} size="xl">
+    <ModalHeader {toggle} class="bg-success text-light">
+        <Icon name="laptop-fill" />
+        Solution du défi
+        {#if exercice}
+            : {exercice.title}
+        {/if}
+    </ModalHeader>
+    <ModalBody>
+        {@html resolution}
+    </ModalBody>
+</Modal>