Update branding to show support for Ukraine

svelte/src/file_viewer/UkrainePopup.svelte

@@ -0,0 +1,45 @@
+<script>
+import { onMount } from "svelte";
+import { fade } from "svelte/transition";
+
+let visible = false
+
+const close = () => {
+	localStorage.setItem("ukraine_popup_dismissed", "🇺🇦")
+	visible = false
+}
+onMount(() => {
+	if (localStorage.getItem("ukraine_popup_dismissed") !== "🇺🇦") {
+		visible = true
+	}
+})
+</script>
+
+{#if visible}
+	<div in:fade out:fade class="notice highlight_yellow">
+		<div class="text">
+			🇺🇦 Russia has invaded Ukraine and is murdering its citizens! 🇺🇦<br/>
+			There are a number of ways you can help:
+			<a href="https://helpukrainewin.org/" rel="noreferrer" target="_blank">Click here for more information</a>.
+		</div>
+		<button on:click={close} class="close button_highlight round">
+			<i class="icon">close</i>
+		</button>
+	</div>
+{/if}
+
+<style>
+.notice {
+	display: flex;
+	flex-direction: row;
+	align-items: center;
+}
+.text {
+	display: inline;
+	flex: 1 1 auto;
+}
+.close {
+	flex: 0 0 auto;
+	margin: 0;
+}
+</style>