Break message layouts out into separate compontents

src/components/messages/RoomTopicChanged.vue

@@ -0,0 +1,19 @@
+<template>
+  <!-- ROOM TOPIC CHANGED -->
+  <div class="statusEvent">
+    {{ stateEventDisplayName(event) }} changed topic to
+    {{ event.getContent().topic }}
+  </div>
+</template>
+
+<script>
+import messageMixin from "./messageMixin";
+
+export default {
+  mixins: [messageMixin],
+};
+</script>
+
+<style lang="scss">
+@import "@/assets/css/chat.scss";
+</style>