frontend: improve launch UI and refactor stream to new page

frontend/src/routes/stream/+page.svelte

@@ -0,0 +1,26 @@
+<script lang="ts">
+	import Stream from './Stream.svelte';
+	import { streamStore } from '../stores/streamStore.svelte';
+
+	$: url = streamStore.Url;
+	$: certHash = streamStore.CertHash;
+</script>
+
+<svelte:head>
+	<title>Stream</title>
+	<meta name="description" content="Streaming game" />
+</svelte:head>
+
+<section>
+	<Stream {url} {certHash} />
+</section>
+
+<style>
+	section {
+		display: flex;
+		flex-direction: column;
+		justify-content: center;
+		align-items: center;
+		flex: 0.6;
+	}
+</style>