Refactor + add message box.

src/components/common/user/UserShort.tsx

@@ -0,0 +1,14 @@
+import { User } from "revolt.js";
+import UserIcon from "./UserIcon";
+import { Text } from "preact-i18n";
+
+export function Username({ user }: { user?: User }) {
+    return <b>{ user?.username ?? <Text id="app.main.channel.unknown_user" /> }</b>;
+}
+
+export default function UserShort({ user }: { user?: User }) {
+    return <>
+        <UserIcon size={24} target={user} />
+        <Username user={user} />
+    </>;
+}