Moves conversation.getProps out of models

Co-authored-by: Scott Nonnenberg <scott@signal.org>

ts/util/getAboutText.ts

@@ -0,0 +1,24 @@
+// Copyright 2023 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import type { ConversationAttributesType } from '../model-types';
+
+export function getAboutText(
+  attributes: ConversationAttributesType
+): string | undefined {
+  if (!attributes.about) {
+    return undefined;
+  }
+
+  const emoji = attributes.aboutEmoji;
+  const text = attributes.about;
+
+  if (!emoji) {
+    return text;
+  }
+
+  return window.i18n('icu:message--getNotificationText--text-with-emoji', {
+    text,
+    emoji,
+  });
+}